get_compat_ipc_perm
if (get_compat_ipc_perm(&out->msg_perm, &p->msg_perm))
return get_compat_ipc_perm(&out->sem_perm, &p->sem_perm);
return get_compat_ipc_perm(&out->shm_perm, &p->shm_perm);
int get_compat_ipc_perm(struct ipc64_perm *, struct compat_ipc_perm __user *);