compat_robust_list
struct compat_robust_list list;
tsk->compat_robust_list = NULL;
struct compat_robust_list_head __user *compat_robust_list;
struct compat_robust_list_head __user *head = curr->compat_robust_list;
if (unlikely(tsk->compat_robust_list)) {
tsk->compat_robust_list = NULL;
return p->compat_robust_list;
current->compat_robust_list = head;