do_sys_mkdirat
static int do_sys_mkdirat(struct lwp *l, int, const char *, mode_t,
return do_sys_mkdirat(l, AT_FDCWD, SCARG(uap, path),
return do_sys_mkdirat(l, SCARG(uap, fd), SCARG(uap, path),
return do_sys_mkdirat(NULL, AT_FDCWD, path, mode, seg);