From ef5d4707b9065c0cf8a69fa3716893f3b75201ba Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 3 Jul 2006 00:24:55 -0700 Subject: [PATCH] [PATCH] lockdep: prove mutex locking correctness Use the lock validator framework to prove mutex locking correctness. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mutex-debug.h | 8 +++++++- include/linux/mutex.h | 31 ++++++++++++++++++++++++++++--- kernel/mutex-debug.c | 6 +++++- kernel/mutex.c | 28 ++++++++++++++++++++++------ kernel/mutex.h | 2 +- 5 files changed, 63 insertions(+), 12 deletions(-) diff --git a/include/linux/mutex-debug.h b/include/linux/mutex-debug.h index 70a26091fc..2537285e10 100644 --- a/include/linux/mutex-debug.h +++ b/include/linux/mutex-debug.h @@ -2,6 +2,7 @@ #define __LINUX_MUTEX_DEBUG_H #include +#include /* * Mutexes - debugging helpers: @@ -10,7 +11,12 @@ #define __DEBUG_MUTEX_INITIALIZER(lockname) \ , .magic = &lockname -#define mutex_init(sem) __mutex_init(sem, __FILE__":"#sem) +#define mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + \ + __mutex_init((mutex), #mutex, &__key); \ +} while (0) extern void FASTCALL(mutex_destroy(struct mutex *lock)); diff --git a/include/linux/mutex.h b/include/linux/mutex.h index caafecd5e3..27c48daa31 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -13,6 +13,7 @@ #include #include #include +#include #include @@ -53,6 +54,9 @@ struct mutex { const char *name; void *magic; #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif }; /* @@ -72,20 +76,34 @@ struct mutex_waiter { # include #else # define __DEBUG_MUTEX_INITIALIZER(lockname) -# define mutex_init(mutex) __mutex_init(mutex, NULL) +# define mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + \ + __mutex_init((mutex), #mutex, &__key); \ +} while (0) # define mutex_destroy(mutex) do { } while (0) #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) \ + , .dep_map = { .name = #lockname } +#else +# define __DEP_MAP_MUTEX_INITIALIZER(lockname) +#endif + #define __MUTEX_INITIALIZER(lockname) \ { .count = ATOMIC_INIT(1) \ , .wait_lock = SPIN_LOCK_UNLOCKED \ , .wait_list = LIST_HEAD_INIT(lockname.wait_list) \ - __DEBUG_MUTEX_INITIALIZER(lockname) } + __DEBUG_MUTEX_INITIALIZER(lockname) \ + __DEP_MAP_MUTEX_INITIALIZER(lockname) } #define DEFINE_MUTEX(mutexname) \ struct mutex mutexname = __MUTEX_INITIALIZER(mutexname) -extern void fastcall __mutex_init(struct mutex *lock, const char *name); +extern void __mutex_init(struct mutex *lock, const char *name, + struct lock_class_key *key); /*** * mutex_is_locked - is the mutex locked @@ -104,6 +122,13 @@ static inline int fastcall mutex_is_locked(struct mutex *lock) */ extern void fastcall mutex_lock(struct mutex *lock); extern int fastcall mutex_lock_interruptible(struct mutex *lock); + +#ifdef CONFIG_DEBUG_LOCK_ALLOC +extern void mutex_lock_nested(struct mutex *lock, unsigned int subclass); +#else +# define mutex_lock_nested(lock, subclass) mutex_lock(lock) +#endif + /* * NOTE: mutex_trylock() follows the spin_trylock() convention, * not the down_trylock() convention! diff --git a/kernel/mutex-debug.c b/kernel/mutex-debug.c index 5569766a1e..e3203c654d 100644 --- a/kernel/mutex-debug.c +++ b/kernel/mutex-debug.c @@ -83,12 +83,16 @@ void debug_mutex_unlock(struct mutex *lock) DEBUG_LOCKS_WARN_ON(lock->owner != current_thread_info()); } -void debug_mutex_init(struct mutex *lock, const char *name) +void debug_mutex_init(struct mutex *lock, const char *name, + struct lock_class_key *key) { +#ifdef CONFIG_DEBUG_LOCK_ALLOC /* * Make sure we are not reinitializing a held lock: */ debug_check_no_locks_freed((void *)lock, sizeof(*lock)); + lockdep_init_map(&lock->dep_map, name, key); +#endif lock->owner = NULL; lock->magic = lock; } diff --git a/kernel/mutex.c b/kernel/mutex.c index 43a50c1870..8c71cf72a4 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -39,13 +39,14 @@ * * It is not allowed to initialize an already locked mutex. */ -__always_inline void fastcall __mutex_init(struct mutex *lock, const char *name) +void +__mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key) { atomic_set(&lock->count, 1); spin_lock_init(&lock->wait_lock); INIT_LIST_HEAD(&lock->wait_list); - debug_mutex_init(lock, name); + debug_mutex_init(lock, name, key); } EXPORT_SYMBOL(__mutex_init); @@ -131,6 +132,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass) spin_lock_mutex(&lock->wait_lock, flags); debug_mutex_lock_common(lock, &waiter); + mutex_acquire(&lock->dep_map, subclass, 0, _RET_IP_); debug_mutex_add_waiter(lock, &waiter, task->thread_info); /* add waiting tasks to the end of the waitqueue (FIFO): */ @@ -158,6 +160,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass) if (unlikely(state == TASK_INTERRUPTIBLE && signal_pending(task))) { mutex_remove_waiter(lock, &waiter, task->thread_info); + mutex_release(&lock->dep_map, 1, _RET_IP_); spin_unlock_mutex(&lock->wait_lock, flags); debug_mutex_free_waiter(&waiter); @@ -194,16 +197,28 @@ __mutex_lock_slowpath(atomic_t *lock_count) __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, 0); } +#ifdef CONFIG_DEBUG_LOCK_ALLOC +void __sched +mutex_lock_nested(struct mutex *lock, unsigned int subclass) +{ + might_sleep(); + __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE, subclass); +} + +EXPORT_SYMBOL_GPL(mutex_lock_nested); +#endif + /* * Release the lock, slowpath: */ static fastcall inline void -__mutex_unlock_common_slowpath(atomic_t *lock_count) +__mutex_unlock_common_slowpath(atomic_t *lock_count, int nested) { struct mutex *lock = container_of(lock_count, struct mutex, count); unsigned long flags; spin_lock_mutex(&lock->wait_lock, flags); + mutex_release(&lock->dep_map, nested, _RET_IP_); debug_mutex_unlock(lock); /* @@ -236,7 +251,7 @@ __mutex_unlock_common_slowpath(atomic_t *lock_count) static fastcall noinline void __mutex_unlock_slowpath(atomic_t *lock_count) { - __mutex_unlock_common_slowpath(lock_count); + __mutex_unlock_common_slowpath(lock_count, 1); } /* @@ -287,9 +302,10 @@ static inline int __mutex_trylock_slowpath(atomic_t *lock_count) spin_lock_mutex(&lock->wait_lock, flags); prev = atomic_xchg(&lock->count, -1); - if (likely(prev == 1)) + if (likely(prev == 1)) { debug_mutex_set_owner(lock, current_thread_info()); - + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + } /* Set it back to 0 if there are no waiters: */ if (likely(list_empty(&lock->wait_list))) atomic_set(&lock->count, 0); diff --git a/kernel/mutex.h b/kernel/mutex.h index aeb2d916aa..a075dafbb2 100644 --- a/kernel/mutex.h +++ b/kernel/mutex.h @@ -22,7 +22,7 @@ #define debug_mutex_free_waiter(waiter) do { } while (0) #define debug_mutex_add_waiter(lock, waiter, ti) do { } while (0) #define debug_mutex_unlock(lock) do { } while (0) -#define debug_mutex_init(lock, name) do { } while (0) +#define debug_mutex_init(lock, name, key) do { } while (0) static inline void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) -- 2.39.5