NTSTATUS __stdcall MI_TIGHTER_PERMISSIONS(_MMPTE OldPte, _MMPTE NewPte){
return(NewPte.u.Long & 0x40) == 0 && (OldPte.u.Long & 0x40) != 0
|| (NewPte.u.Long & 2) == 0 && (OldPte.u.Long & 2) != 0
|| NewPte.u.Hard._bf_0 < 0 && OldPte.u.Hard._bf_0 >= 0;
}