diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index be2df9ea7c30..84d5b649b95f 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -1091,7 +1091,7 @@ rwsem_down_read_slowpath(struct rw_semaphore *sem, long count, unsigned int stat /* Ordered by sem->wait_lock against rwsem_mark_wake(). */ break; } - schedule(); + schedule_preempt_disabled(); lockevent_inc(rwsem_sleep_reader); } @@ -1253,14 +1253,20 @@ static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem) */ static inline int __down_read_common(struct rw_semaphore *sem, int state) { + int ret = 0; long count; + preempt_disable(); if (!rwsem_read_trylock(sem, &count)) { - if (IS_ERR(rwsem_down_read_slowpath(sem, count, state))) - return -EINTR; + if (IS_ERR(rwsem_down_read_slowpath(sem, count, state))) { + ret = -EINTR; + goto out; + } DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); } - return 0; +out: + preempt_enable(); + return ret; } static inline void __down_read(struct rw_semaphore *sem) @@ -1280,19 +1286,23 @@ static inline int __down_read_killable(struct rw_semaphore *sem) static inline int __down_read_trylock(struct rw_semaphore *sem) { + int ret = 0; long tmp; DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem); + preempt_disable(); tmp = atomic_long_read(&sem->count); while (!(tmp & RWSEM_READ_FAILED_MASK)) { if (atomic_long_try_cmpxchg_acquire(&sem->count, &tmp, tmp + RWSEM_READER_BIAS)) { rwsem_set_reader_owned(sem); - return 1; + ret = 1; + break; } } - return 0; + preempt_enable(); + return ret; } /* @@ -1334,6 +1344,7 @@ static inline void __up_read(struct rw_semaphore *sem) DEBUG_RWSEMS_WARN_ON(sem->magic != sem, sem); DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem); + preempt_disable(); rwsem_clear_reader_owned(sem); tmp = atomic_long_add_return_release(-RWSEM_READER_BIAS, &sem->count); DEBUG_RWSEMS_WARN_ON(tmp < 0, sem); @@ -1342,6 +1353,7 @@ static inline void __up_read(struct rw_semaphore *sem) clear_nonspinnable(sem); rwsem_wake(sem); } + preempt_enable(); } /* @@ -1661,6 +1673,12 @@ void down_read_non_owner(struct rw_semaphore *sem) { might_sleep(); __down_read(sem); + /* + * The owner value for a reader-owned lock is mostly for debugging + * purpose only and is not critical to the correct functioning of + * rwsem. So it is perfectly fine to set it in a preempt-enabled + * context here. + */ __rwsem_set_reader_owned(sem, NULL); } EXPORT_SYMBOL(down_read_non_owner);