-static inline bool in_vfork(struct task_struct *tsk)
-{
- bool ret;
-
- /*
- * need RCU to access ->real_parent if CLONE_VM was used along with
- * CLONE_PARENT.
- *
- * We check real_parent->mm == tsk->mm because CLONE_VFORK does not
- * imply CLONE_VM
- *
- * CLONE_VFORK can be used with CLONE_PARENT/CLONE_THREAD and thus
- * ->real_parent is not necessarily the task doing vfork(), so in
- * theory we can't rely on task_lock() if we want to dereference it.
- *
- * And in this case we can't trust the real_parent->mm == tsk->mm
- * check, it can be false negative. But we do not care, if init or
- * another oom-unkillable task does this it should blame itself.
- */
- rcu_read_lock();
- ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
- rcu_read_unlock();
-
- return ret;
-}
-