[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>

1 files changed, 3 insertions, 9 deletions

diff --git a/include/linux/mutex-debug.h b/include/linux/mutex-debug.h
index 8b5769f00467..70a26091fc73 100644
--- a/include/linux/mutex-debug.h
+++ b/include/linux/mutex-debug.h
@@ -7,17 +7,11 @@
  * Mutexes - debugging helpers:
  */
 
-#define __DEBUG_MUTEX_INITIALIZER(lockname) \
-        , .held_list = LIST_HEAD_INIT(lockname.held_list), \
-          .name = #lockname , .magic = &lockname
+#define __DEBUG_MUTEX_INITIALIZER(lockname)                             \
+        , .magic = &lockname
 
-#define mutex_init(sem)         __mutex_init(sem, __FUNCTION__)
+#define mutex_init(sem)         __mutex_init(sem, __FILE__":"#sem)
 
 extern void FASTCALL(mutex_destroy(struct mutex *lock));
 
-extern void mutex_debug_show_all_locks(void);
-extern void mutex_debug_show_held_locks(struct task_struct *filter);
-extern void mutex_debug_check_no_locks_held(struct task_struct *task);
-extern void mutex_debug_check_no_locks_freed(const void *from, unsigned long len);
-
 #endif