diff options
Diffstat (limited to 'kernel/locking')
| -rw-r--r-- | kernel/locking/rwsem.c | 22 |
1 files changed, 18 insertions, 4 deletions
diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 354238a08b7a..eef04551eae7 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -105,8 +105,9 @@ #ifdef CONFIG_DEBUG_RWSEMS # define DEBUG_RWSEMS_WARN_ON(c, sem) do { \ if (!debug_locks_silent && \ - WARN_ONCE(c, "DEBUG_RWSEMS_WARN_ON(%s): count = 0x%lx, owner = 0x%lx, curr 0x%lx, list %sempty\n",\ + WARN_ONCE(c, "DEBUG_RWSEMS_WARN_ON(%s): count = 0x%lx, magic = 0x%lx, owner = 0x%lx, curr 0x%lx, list %sempty\n",\ #c, atomic_long_read(&(sem)->count), \ + (unsigned long) sem->magic, \ atomic_long_read(&(sem)->owner), (long)current, \ list_empty(&(sem)->wait_list) ? "" : "not ")) \ debug_locks_off(); \ @@ -330,6 +331,9 @@ void __init_rwsem(struct rw_semaphore *sem, const char *name, debug_check_no_locks_freed((void *)sem, sizeof(*sem)); lockdep_init_map(&sem->dep_map, name, key, 0); #endif +#ifdef CONFIG_DEBUG_RWSEMS + sem->magic = sem; +#endif atomic_long_set(&sem->count, RWSEM_UNLOCKED_VALUE); raw_spin_lock_init(&sem->wait_lock); INIT_LIST_HEAD(&sem->wait_list); @@ -1358,11 +1362,14 @@ static inline int __down_read_killable(struct rw_semaphore *sem) static inline int __down_read_trylock(struct rw_semaphore *sem) { + long tmp; + + DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem); + /* * Optimize for the case when the rwsem is not locked at all. */ - long tmp = RWSEM_UNLOCKED_VALUE; - + tmp = RWSEM_UNLOCKED_VALUE; do { if (atomic_long_try_cmpxchg_acquire(&sem->count, &tmp, tmp + RWSEM_READER_BIAS)) { @@ -1403,8 +1410,11 @@ static inline int __down_write_killable(struct rw_semaphore *sem) static inline int __down_write_trylock(struct rw_semaphore *sem) { - long tmp = RWSEM_UNLOCKED_VALUE; + long tmp; + DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem); + + tmp = RWSEM_UNLOCKED_VALUE; if (atomic_long_try_cmpxchg_acquire(&sem->count, &tmp, RWSEM_WRITER_LOCKED)) { rwsem_set_owner(sem); @@ -1420,7 +1430,9 @@ inline void __up_read(struct rw_semaphore *sem) { long tmp; + DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem); DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); + rwsem_clear_reader_owned(sem); tmp = atomic_long_add_return_release(-RWSEM_READER_BIAS, &sem->count); DEBUG_RWSEMS_WARN_ON(tmp < 0, sem); @@ -1438,12 +1450,14 @@ static inline void __up_write(struct rw_semaphore *sem) { long tmp; + DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem); /* * sem->owner may differ from current if the ownership is transferred * to an anonymous writer by setting the RWSEM_NONSPINNABLE bits. */ DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE), sem); + rwsem_clear_owner(sem); tmp = atomic_long_fetch_add_release(-RWSEM_WRITER_LOCKED, &sem->count); if (unlikely(tmp & RWSEM_FLAG_WAITERS)) |