PRIV_IMPL_INFO_SIZE
size_t size = PRIV_IMPL_INFO_SIZE(ip);
ip = alloca(PRIV_IMPL_INFO_SIZE(&ii));
(void) getprivinfo(ip, PRIV_IMPL_INFO_SIZE(&ii));
PRIV_IMPL_INFO_SIZE(ip) - sizeof (priv_impl_info_t));
realsize = PRIV_IMPL_INFO_SIZE(aip);
PRIV_IMPL_INFO_SIZE(ppii) != nbytes) {
pinfosz = PRIV_IMPL_INFO_SIZE(pinfo);