Now that (PI) futexes have their own private RT-mutex interface and implementation we can easily add lockdep annotations to the existing RT-mutex interface. Signed-off-by: Peter Zijlstra (Intel) --- include/linux/rtmutex.h | 25 +++++++++++++++++++++---- kernel/locking/rtmutex-debug.c | 6 +++++- kernel/locking/rtmutex-debug.h | 2 +- kernel/locking/rtmutex.c | 36 +++++++++++++++++++++++++++++------- kernel/locking/rtmutex.h | 2 +- lib/Kconfig.debug | 3 +++ 6 files changed, 60 insertions(+), 14 deletions(-) --- a/include/linux/rtmutex.h +++ b/include/linux/rtmutex.h @@ -37,6 +37,9 @@ struct rt_mutex { int line; void *magic; #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map dep_map; +#endif }; struct rt_mutex_waiter; @@ -58,19 +61,33 @@ struct hrtimer_sleeper; #ifdef CONFIG_DEBUG_RT_MUTEXES # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ , .name = #mutexname, .file = __FILE__, .line = __LINE__ -# define rt_mutex_init(mutex) __rt_mutex_init(mutex, __func__) + +# define rt_mutex_init(mutex) \ +do { \ + static struct lock_class_key __key; \ + __rt_mutex_init(mutex, __func__, &__key); \ +} while (0) + extern void rt_mutex_debug_task_free(struct task_struct *tsk); #else # define __DEBUG_RT_MUTEX_INITIALIZER(mutexname) -# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL) +# define rt_mutex_init(mutex) __rt_mutex_init(mutex, NULL, NULL) # define rt_mutex_debug_task_free(t) do { } while (0) #endif +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) \ + , .dep_map = { .name = #mutexname } +#else +#define __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname) +#endif + #define __RT_MUTEX_INITIALIZER(mutexname) \ { .wait_lock = __RAW_SPIN_LOCK_UNLOCKED(mutexname.wait_lock) \ , .waiters = RB_ROOT \ , .owner = NULL \ - __DEBUG_RT_MUTEX_INITIALIZER(mutexname)} + __DEBUG_RT_MUTEX_INITIALIZER(mutexname) \ + __DEP_MAP_RT_MUTEX_INITIALIZER(mutexname)} #define DEFINE_RT_MUTEX(mutexname) \ struct rt_mutex mutexname = __RT_MUTEX_INITIALIZER(mutexname) @@ -86,7 +103,7 @@ static inline int rt_mutex_is_locked(str return lock->owner != NULL; } -extern void __rt_mutex_init(struct rt_mutex *lock, const char *name); +extern void __rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key); extern void rt_mutex_destroy(struct rt_mutex *lock); extern void rt_mutex_lock(struct rt_mutex *lock); --- a/kernel/locking/rtmutex-debug.c +++ b/kernel/locking/rtmutex-debug.c @@ -166,12 +166,16 @@ void debug_rt_mutex_free_waiter(struct r memset(waiter, 0x22, sizeof(*waiter)); } -void debug_rt_mutex_init(struct rt_mutex *lock, const char *name) +void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key) { /* * Make sure we are not reinitializing a held lock: */ debug_check_no_locks_freed((void *)lock, sizeof(*lock)); lock->name = name; + +#ifdef CONFIG_DEBUG_LOCK_ALLOC + lockdep_init_map(&lock->dep_map, name, key, 0); +#endif } --- a/kernel/locking/rtmutex-debug.h +++ b/kernel/locking/rtmutex-debug.h @@ -11,7 +11,7 @@ extern void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter); extern void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter); -extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name); +extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name, struct lock_class_key *key); extern void debug_rt_mutex_lock(struct rt_mutex *lock); extern void debug_rt_mutex_unlock(struct rt_mutex *lock); extern void debug_rt_mutex_proxy_lock(struct rt_mutex *lock, --- a/kernel/locking/rtmutex.c +++ b/kernel/locking/rtmutex.c @@ -1481,6 +1481,7 @@ void __sched rt_mutex_lock(struct rt_mut { might_sleep(); + mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, rt_mutex_slowlock); } EXPORT_SYMBOL_GPL(rt_mutex_lock); @@ -1496,9 +1497,16 @@ EXPORT_SYMBOL_GPL(rt_mutex_lock); */ int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock) { + int ret; + might_sleep(); - return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock); + mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); + ret = rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE, rt_mutex_slowlock); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + + return ret; } EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible); @@ -1526,11 +1534,18 @@ int __sched rt_mutex_futex_trylock(struc int rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout) { + int ret; + might_sleep(); - return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout, + mutex_acquire(&lock->dep_map, 0, 0, _RET_IP_); + ret = rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout, RT_MUTEX_MIN_CHAINWALK, rt_mutex_slowlock); + if (ret) + mutex_release(&lock->dep_map, 1, _RET_IP_); + + return ret; } EXPORT_SYMBOL_GPL(rt_mutex_timed_lock); @@ -1547,10 +1562,16 @@ EXPORT_SYMBOL_GPL(rt_mutex_timed_lock); */ int __sched rt_mutex_trylock(struct rt_mutex *lock) { + int ret; + if (WARN_ON_ONCE(in_irq() || in_nmi() || in_serving_softirq())) return 0; - return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock); + ret = rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock); + if (ret) + mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); + + return ret; } EXPORT_SYMBOL_GPL(rt_mutex_trylock); @@ -1561,6 +1582,7 @@ EXPORT_SYMBOL_GPL(rt_mutex_trylock); */ void __sched rt_mutex_unlock(struct rt_mutex *lock) { + mutex_release(&lock->dep_map, 1, _RET_IP_); rt_mutex_fastunlock(lock, rt_mutex_slowunlock); } EXPORT_SYMBOL_GPL(rt_mutex_unlock); @@ -1620,7 +1642,6 @@ void rt_mutex_destroy(struct rt_mutex *l lock->magic = NULL; #endif } - EXPORT_SYMBOL_GPL(rt_mutex_destroy); /** @@ -1632,14 +1653,15 @@ EXPORT_SYMBOL_GPL(rt_mutex_destroy); * * Initializing of a locked rt lock is not allowed */ -void __rt_mutex_init(struct rt_mutex *lock, const char *name) +void __rt_mutex_init(struct rt_mutex *lock, const char *name, + struct lock_class_key *key) { lock->owner = NULL; raw_spin_lock_init(&lock->wait_lock); lock->waiters = RB_ROOT; lock->waiters_leftmost = NULL; - debug_rt_mutex_init(lock, name); + debug_rt_mutex_init(lock, name, key); } EXPORT_SYMBOL_GPL(__rt_mutex_init); @@ -1660,7 +1682,7 @@ EXPORT_SYMBOL_GPL(__rt_mutex_init); void rt_mutex_init_proxy_locked(struct rt_mutex *lock, struct task_struct *proxy_owner) { - __rt_mutex_init(lock, NULL); + __rt_mutex_init(lock, NULL, NULL); debug_rt_mutex_proxy_lock(lock, proxy_owner); rt_mutex_set_owner(lock, proxy_owner); } --- a/kernel/locking/rtmutex.h +++ b/kernel/locking/rtmutex.h @@ -17,7 +17,7 @@ #define debug_rt_mutex_proxy_lock(l,p) do { } while (0) #define debug_rt_mutex_proxy_unlock(l) do { } while (0) #define debug_rt_mutex_unlock(l) do { } while (0) -#define debug_rt_mutex_init(m, n) do { } while (0) +#define debug_rt_mutex_init(m, n, k) do { } while (0) #define debug_rt_mutex_deadlock(d, a ,l) do { } while (0) #define debug_rt_mutex_print_deadlock(w) do { } while (0) #define debug_rt_mutex_reset_waiter(w) do { } while (0) --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1052,6 +1052,7 @@ config DEBUG_LOCK_ALLOC depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT select DEBUG_SPINLOCK select DEBUG_MUTEXES + select DEBUG_RT_MUTEXES if RT_MUTEXES select LOCKDEP help This feature will check whether any held lock (spinlock, rwlock, @@ -1067,6 +1068,7 @@ config PROVE_LOCKING select LOCKDEP select DEBUG_SPINLOCK select DEBUG_MUTEXES + select DEBUG_RT_MUTEXES if RT_MUTEXES select DEBUG_LOCK_ALLOC select TRACE_IRQFLAGS default n @@ -1121,6 +1123,7 @@ config LOCK_STAT select LOCKDEP select DEBUG_SPINLOCK select DEBUG_MUTEXES + select DEBUG_RT_MUTEXES if RT_MUTEXES select DEBUG_LOCK_ALLOC default n help