[PATCH] lockdep: better lock debugging
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>
diff --git a/kernel/mutex-debug.h b/kernel/mutex-debug.h
index bdab13a..babfbdf 100644
--- a/kernel/mutex-debug.h
+++ b/kernel/mutex-debug.h
@@ -10,102 +10,44 @@
* More details are in kernel/mutex-debug.c.
*/
-extern spinlock_t debug_mutex_lock;
-extern struct list_head debug_mutex_held_locks;
-extern int debug_mutex_on;
-
-/*
- * In the debug case we carry the caller's instruction pointer into
- * other functions, but we dont want the function argument overhead
- * in the nondebug case - hence these macros:
- */
-#define __IP_DECL__ , unsigned long ip
-#define __IP__ , ip
-#define __RET_IP__ , (unsigned long)__builtin_return_address(0)
-
/*
* This must be called with lock->wait_lock held.
*/
-extern void debug_mutex_set_owner(struct mutex *lock,
- struct thread_info *new_owner __IP_DECL__);
+extern void
+debug_mutex_set_owner(struct mutex *lock, struct thread_info *new_owner);
static inline void debug_mutex_clear_owner(struct mutex *lock)
{
lock->owner = NULL;
}
-extern void debug_mutex_init_waiter(struct mutex_waiter *waiter);
+extern void debug_mutex_lock_common(struct mutex *lock,
+ struct mutex_waiter *waiter);
extern void debug_mutex_wake_waiter(struct mutex *lock,
struct mutex_waiter *waiter);
extern void debug_mutex_free_waiter(struct mutex_waiter *waiter);
extern void debug_mutex_add_waiter(struct mutex *lock,
struct mutex_waiter *waiter,
- struct thread_info *ti __IP_DECL__);
+ struct thread_info *ti);
extern void mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter,
struct thread_info *ti);
extern void debug_mutex_unlock(struct mutex *lock);
-extern void debug_mutex_init(struct mutex *lock, const char *name);
-
-#define debug_spin_lock_save(lock, flags) \
- do { \
- local_irq_save(flags); \
- if (debug_mutex_on) \
- spin_lock(lock); \
- } while (0)
-
-#define debug_spin_unlock_restore(lock, flags) \
- do { \
- if (debug_mutex_on) \
- spin_unlock(lock); \
- local_irq_restore(flags); \
- preempt_check_resched(); \
- } while (0)
+extern void debug_mutex_init(struct mutex *lock, const char *name,
+ struct lock_class_key *key);
#define spin_lock_mutex(lock, flags) \
do { \
struct mutex *l = container_of(lock, struct mutex, wait_lock); \
\
DEBUG_LOCKS_WARN_ON(in_interrupt()); \
- debug_spin_lock_save(&debug_mutex_lock, flags); \
- spin_lock(lock); \
+ local_irq_save(flags); \
+ __raw_spin_lock(&(lock)->raw_lock); \
DEBUG_LOCKS_WARN_ON(l->magic != l); \
} while (0)
#define spin_unlock_mutex(lock, flags) \
do { \
- spin_unlock(lock); \
- debug_spin_unlock_restore(&debug_mutex_lock, flags); \
+ __raw_spin_unlock(&(lock)->raw_lock); \
+ local_irq_restore(flags); \
+ preempt_check_resched(); \
} while (0)
-
-#define DEBUG_OFF() \
-do { \
- if (debug_mutex_on) { \
- debug_mutex_on = 0; \
- console_verbose(); \
- if (spin_is_locked(&debug_mutex_lock)) \
- spin_unlock(&debug_mutex_lock); \
- } \
-} while (0)
-
-#define DEBUG_BUG() \
-do { \
- if (debug_mutex_on) { \
- DEBUG_OFF(); \
- BUG(); \
- } \
-} while (0)
-
-#define DEBUG_LOCKS_WARN_ON(c) \
-do { \
- if (unlikely(c && debug_mutex_on)) { \
- DEBUG_OFF(); \
- WARN_ON(1); \
- } \
-} while (0)
-
-#ifdef CONFIG_SMP
-# define SMP_DEBUG_LOCKS_WARN_ON(c) DEBUG_LOCKS_WARN_ON(c)
-#else
-# define SMP_DEBUG_LOCKS_WARN_ON(c) do { } while (0)
-#endif
-