[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, 0 insertions, 6 deletions

diff --git a/include/linux/mutex.h b/include/linux/mutex.h
index f1ac507fa20d..caafecd5e366 100644
--- a/include/linux/mutex.h
+++ b/include/linux/mutex.h
@@ -50,8 +50,6 @@ struct mutex {
         struct list_head        wait_list;
 #ifdef CONFIG_DEBUG_MUTEXES
         struct thread_info      *owner;
-        struct list_head        held_list;
-        unsigned long           acquire_ip;
         const char              *name;
         void                    *magic;
 #endif
@@ -76,10 +74,6 @@ struct mutex_waiter {
 # define __DEBUG_MUTEX_INITIALIZER(lockname)
 # define mutex_init(mutex)                      __mutex_init(mutex, NULL)
 # define mutex_destroy(mutex)                           do { } while (0)
-# define mutex_debug_show_all_locks()                   do { } while (0)
-# define mutex_debug_show_held_locks(p)                 do { } while (0)
-# define mutex_debug_check_no_locks_held(task)          do { } while (0)
-# define mutex_debug_check_no_locks_freed(from, len)    do { } while (0)
 #endif
 
 #define __MUTEX_INITIALIZER(lockname) \