forked from luck/tmp_suning_uos_patched
fb7e42413a
With the lock validator we detect mutex deadlocks (and more), the mutex deadlock checking code is both redundant and slower. So remove it. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
148 lines
4.0 KiB
C
148 lines
4.0 KiB
C
/*
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* kernel/mutex-debug.c
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*
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* Debugging code for mutexes
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*
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* Started by Ingo Molnar:
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*
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* Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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*
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* lock debugging, locking tree, deadlock detection started by:
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*
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* Copyright (C) 2004, LynuxWorks, Inc., Igor Manyilov, Bill Huey
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* Released under the General Public License (GPL).
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*/
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#include <linux/mutex.h>
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#include <linux/sched.h>
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/poison.h>
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#include <linux/spinlock.h>
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#include <linux/kallsyms.h>
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#include <linux/interrupt.h>
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#include "mutex-debug.h"
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/*
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* We need a global lock when we walk through the multi-process
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* lock tree. Only used in the deadlock-debugging case.
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*/
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DEFINE_SPINLOCK(debug_mutex_lock);
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/*
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* All locks held by all tasks, in a single global list:
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*/
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LIST_HEAD(debug_mutex_held_locks);
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/*
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* In the debug case we carry the caller's instruction pointer into
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* other functions, but we dont want the function argument overhead
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* in the nondebug case - hence these macros:
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*/
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#define __IP_DECL__ , unsigned long ip
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#define __IP__ , ip
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#define __RET_IP__ , (unsigned long)__builtin_return_address(0)
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/*
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* "mutex debugging enabled" flag. We turn it off when we detect
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* the first problem because we dont want to recurse back
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* into the tracing code when doing error printk or
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* executing a BUG():
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*/
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int debug_mutex_on = 1;
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/*
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* Must be called with lock->wait_lock held.
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*/
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void debug_mutex_set_owner(struct mutex *lock,
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struct thread_info *new_owner __IP_DECL__)
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{
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lock->owner = new_owner;
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DEBUG_LOCKS_WARN_ON(!list_empty(&lock->held_list));
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if (debug_mutex_on) {
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list_add_tail(&lock->held_list, &debug_mutex_held_locks);
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lock->acquire_ip = ip;
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}
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}
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void debug_mutex_init_waiter(struct mutex_waiter *waiter)
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{
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memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
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waiter->magic = waiter;
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INIT_LIST_HEAD(&waiter->list);
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}
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void debug_mutex_wake_waiter(struct mutex *lock, struct mutex_waiter *waiter)
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{
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SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
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DEBUG_LOCKS_WARN_ON(list_empty(&lock->wait_list));
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DEBUG_LOCKS_WARN_ON(waiter->magic != waiter);
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DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
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}
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void debug_mutex_free_waiter(struct mutex_waiter *waiter)
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{
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DEBUG_LOCKS_WARN_ON(!list_empty(&waiter->list));
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memset(waiter, MUTEX_DEBUG_FREE, sizeof(*waiter));
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}
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void debug_mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter,
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struct thread_info *ti __IP_DECL__)
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{
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SMP_DEBUG_LOCKS_WARN_ON(!spin_is_locked(&lock->wait_lock));
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/* Mark the current thread as blocked on the lock: */
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ti->task->blocked_on = waiter;
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waiter->lock = lock;
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}
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void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
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struct thread_info *ti)
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{
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DEBUG_LOCKS_WARN_ON(list_empty(&waiter->list));
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DEBUG_LOCKS_WARN_ON(waiter->task != ti->task);
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DEBUG_LOCKS_WARN_ON(ti->task->blocked_on != waiter);
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ti->task->blocked_on = NULL;
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list_del_init(&waiter->list);
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waiter->task = NULL;
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}
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void debug_mutex_unlock(struct mutex *lock)
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{
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DEBUG_LOCKS_WARN_ON(lock->magic != lock);
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DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
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DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info());
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if (debug_mutex_on) {
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DEBUG_LOCKS_WARN_ON(list_empty(&lock->held_list));
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list_del_init(&lock->held_list);
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}
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}
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void debug_mutex_init(struct mutex *lock, const char *name)
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{
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/*
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* Make sure we are not reinitializing a held lock:
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*/
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mutex_debug_check_no_locks_freed((void *)lock, sizeof(*lock));
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lock->owner = NULL;
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INIT_LIST_HEAD(&lock->held_list);
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lock->name = name;
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lock->magic = lock;
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}
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/***
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* mutex_destroy - mark a mutex unusable
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* @lock: the mutex to be destroyed
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*
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* This function marks the mutex uninitialized, and any subsequent
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* use of the mutex is forbidden. The mutex must not be locked when
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* this function is called.
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*/
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void fastcall mutex_destroy(struct mutex *lock)
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{
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DEBUG_LOCKS_WARN_ON(mutex_is_locked(lock));
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lock->magic = NULL;
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}
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EXPORT_SYMBOL_GPL(mutex_destroy);
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