[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>
This commit is contained in:
Ingo Molnar
2006-07-03 00:24:33 -07:00
committed by Linus Torvalds
parent fb7e42413a
commit 9a11b49a80
25 changed files with 264 additions and 566 deletions

View File

@ -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