buf := make([]byte, kind.initialSize())
	for {
		errno := f(buf)
		if errno == 0 {
			return nil
		} else if runtime.GOOS == "aix" && errno+1 == 0 {
			// On AIX getpwuid_r appears to return -1,
			// not ERANGE, on buffer overflow.
		} else if errno != syscall.ERANGE {
			return errno
		}
		newSize := len(buf) * 2
		if !isSizeReasonable(int64(newSize)) {