-static inline void lock_semundo(void)
-{
- struct sem_undo_list *undo_list;
-
- undo_list = current->sysvsem.undo_list;
- if (undo_list)
- spin_lock(&undo_list->lock);
-}
-
-/* This code has an interaction with copy_semundo().
- * Consider; two tasks are sharing the undo_list. task1
- * acquires the undo_list lock in lock_semundo(). If task2 now
- * exits before task1 releases the lock (by calling
- * unlock_semundo()), then task1 will never call spin_unlock().
- * This leave the sem_undo_list in a locked state. If task1 now creats task3
- * and once again shares the sem_undo_list, the sem_undo_list will still be
- * locked, and future SEM_UNDO operations will deadlock. This case is
- * dealt with in copy_semundo() by having it reinitialize the spin lock when
- * the refcnt goes from 1 to 2.
- */
-static inline void unlock_semundo(void)
-{
- struct sem_undo_list *undo_list;
-
- undo_list = current->sysvsem.undo_list;
- if (undo_list)
- spin_unlock(&undo_list->lock);
-}
-
-