cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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mutex-debug.c (2842B)

      1/*
      2 * Debugging code for mutexes
      3 *
      4 * Started by Ingo Molnar:
      5 *
      6 *  Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
      7 *
      8 * lock debugging, locking tree, deadlock detection started by:
      9 *
     10 *  Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
     11 *  Released under the General Public License (GPL).
     12 */
     13#include <linux/mutex.h>
     14#include <linux/delay.h>
     15#include <linux/export.h>
     16#include <linux/poison.h>
     17#include <linux/sched.h>
     18#include <linux/spinlock.h>
     19#include <linux/kallsyms.h>
     20#include <linux/interrupt.h>
     21#include <linux/debug_locks.h>
     22
     23#include "mutex.h"
     24
     25/*
     26 * Must be called with lock->wait_lock held.
     27 */
     28void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
     29{
     30	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
     31	waiter->magic = waiter;
     32	INIT_LIST_HEAD(&waiter->list);
     33	waiter->ww_ctx = MUTEX_POISON_WW_CTX;
     34}
     35
     36void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
     37{
     38	lockdep_assert_held(&lock->wait_lock);
     39	DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
     40	DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
     41	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
     42}
     43
     44void debug_mutex_free_waiter(struct mutex_waiter *waiter)
     45{
     46	DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
     47	memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
     48}
     49
     50void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
     51			    struct task_struct *task)
     52{
     53	lockdep_assert_held(&lock->wait_lock);
     54
     55	/* Mark the current thread as blocked on the lock: */
     56	task->blocked_on = waiter;
     57}
     58
     59void debug_mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
     60			 struct task_struct *task)
     61{
     62	DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
     63	DEBUG_LOCKS_WARN_ON(waiter->task != task);
     64	DEBUG_LOCKS_WARN_ON(task->blocked_on != waiter);
     65	task->blocked_on = NULL;
     66
     67	INIT_LIST_HEAD(&waiter->list);
     68	waiter->task = NULL;
     69}
     70
     71void debug_mutex_unlock(struct mutex *lock)
     72{
     73	if (likely(debug_locks)) {
     74		DEBUG_LOCKS_WARN_ON(lock->magic != lock);
     75		DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
     76	}
     77}
     78
     79void debug_mutex_init(struct mutex *lock, const char *name,
     80		      struct lock_class_key *key)
     81{
     82#ifdef CONFIG_DEBUG_LOCK_ALLOC
     83	/*
     84	 * Make sure we are not reinitializing a held lock:
     85	 */
     86	debug_check_no_locks_freed((void *)lock, sizeof(*lock));
     87	lockdep_init_map_wait(&lock->dep_map, name, key, 0, LD_WAIT_SLEEP);
     88#endif
     89	lock->magic = lock;
     90}
     91
     92/***
     93 * mutex_destroy - mark a mutex unusable
     94 * @lock: the mutex to be destroyed
     95 *
     96 * This function marks the mutex uninitialized, and any subsequent
     97 * use of the mutex is forbidden. The mutex must not be locked when
     98 * this function is called.
     99 */
    100void mutex_destroy(struct mutex *lock)
    101{
    102	DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
    103	lock->magic = NULL;
    104}
    105
    106EXPORT_SYMBOL_GPL(mutex_destroy);