_mutex_lock_killable
extern int __must_check _mutex_lock_killable(struct mutex *lock,
#define mutex_lock_killable(lock) _mutex_lock_killable(lock, 0, NULL)
_mutex_lock_killable(lock, 0, &(nest_lock)->dep_map) \
_mutex_lock_killable(lock, subclass, NULL)
EXPORT_SYMBOL_GPL(_mutex_lock_killable);
EXPORT_SYMBOL_GPL(_mutex_lock_killable);