9a11b49a80
Generic lock debugging:
- generalized lock debugging framework. For example, a bug in one lock
subsystem turns off debugging in all lock subsystems.
- got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from
the mutex/rtmutex debugging code: it caused way too much prototype
hackery, and lockdep will give the same information anyway.
- ability to do silent tests
- check lock freeing in vfree too.
- more finegrained debugging options, to allow distributions to
turn off more expensive debugging features.
There's no separate 'held mutexes' list anymore - but there's a 'held locks'
stack within lockdep, which unifies deadlock detection across all lock
classes. (this is independent of the lockdep validation stuff - lockdep first
checks whether we are holding a lock already)
Here are the current debugging options:
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
which do:
config DEBUG_MUTEXES
bool "Mutex debugging, basic checks"
config DEBUG_LOCK_ALLOC
bool "Detect incorrect freeing of live mutexes"
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
108 lines
3 KiB
C
108 lines
3 KiB
C
/*
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* RT Mutexes: blocking mutual exclusion locks with PI support
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*
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* started by Ingo Molnar and Thomas Gleixner:
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*
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* Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
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* Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
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*
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* This file contains the public data structure and API definitions.
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*/
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#ifndef __LINUX_RT_MUTEX_H
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#define __LINUX_RT_MUTEX_H
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#include <linux/linkage.h>
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#include <linux/plist.h>
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#include <linux/spinlock_types.h>
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/*
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* The rt_mutex structure
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*
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* @wait_lock: spinlock to protect the structure
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* @wait_list: pilist head to enqueue waiters in priority order
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* @owner: the mutex owner
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*/
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struct rt_mutex {
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spinlock_t wait_lock;
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struct plist_head wait_list;
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struct task_struct *owner;
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#ifdef CONFIG_DEBUG_RT_MUTEXES
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int save_state;
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const char *name, *file;
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int line;
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void *magic;
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#endif
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};
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struct rt_mutex_waiter;
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struct hrtimer_sleeper;
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#ifdef CONFIG_DEBUG_RT_MUTEXES
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extern int rt_mutex_debug_check_no_locks_freed(const void *from,
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unsigned long len);
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extern void rt_mutex_debug_check_no_locks_held(struct task_struct *task);
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#else
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static inline int rt_mutex_debug_check_no_locks_freed(const void *from,
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unsigned long len)
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{
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return 0;
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}
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# define rt_mutex_debug_check_no_locks_held(task) do { } while (0)
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#endif
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#ifdef CONFIG_DEBUG_RT_MUTEXES
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# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \
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, .name = #mutexname, .file = __FILE__, .line = __LINE__
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# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __FUNCTION__)
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extern void rt_mutex_debug_task_free(struct task_struct *tsk);
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#else
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# define __DEBUG_RT_MUTEX_INITIALIZER(mutexname)
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# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL)
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# define rt_mutex_debug_task_free(t) do { } while (0)
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#endif
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#define __RT_MUTEX_INITIALIZER(mutexname) \
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{ .wait_lock = SPIN_LOCK_UNLOCKED \
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, .wait_list = PLIST_HEAD_INIT(mutexname.wait_list, mutexname.wait_lock) \
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, .owner = NULL \
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__DEBUG_RT_MUTEX_INITIALIZER(mutexname)}
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#define DEFINE_RT_MUTEX(mutexname) \
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struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname)
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/***
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* rt_mutex_is_locked - is the mutex locked
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* @lock: the mutex to be queried
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*
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* Returns 1 if the mutex is locked, 0 if unlocked.
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*/
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static inline int rt_mutex_is_locked(struct rt_mutex *lock)
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{
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return lock->owner != NULL;
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}
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extern void __rt_mutex_init(struct rt_mutex *lock, const char *name);
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extern void rt_mutex_destroy(struct rt_mutex *lock);
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extern void rt_mutex_lock(struct rt_mutex *lock);
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extern int rt_mutex_lock_interruptible(struct rt_mutex *lock,
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int detect_deadlock);
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extern int rt_mutex_timed_lock(struct rt_mutex *lock,
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struct hrtimer_sleeper *timeout,
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int detect_deadlock);
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extern int rt_mutex_trylock(struct rt_mutex *lock);
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extern void rt_mutex_unlock(struct rt_mutex *lock);
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#ifdef CONFIG_RT_MUTEXES
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# define INIT_RT_MUTEXES(tsk) \
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.pi_waiters = PLIST_HEAD_INIT(tsk.pi_waiters, tsk.pi_lock), \
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INIT_RT_MUTEX_DEBUG(tsk)
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#else
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# define INIT_RT_MUTEXES(tsk)
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#endif
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#endif
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