Re: [PATCH] waitid system call

Jakub Jelinek
2004-08-31T06:27:18Z

On Mon, Aug 30, 2004 at 11:04:46PM -0700, Roland McGrath wrote:
> + /*
> + * For a WNOHANG return, clear out all the fields
> + * we would set so the user can easily tell the
> + * difference.
> + */
> + if (!retval)
> + retval = put_user(0, &infop->si_signo);
> + if (!retval)
> + retval = put_user(0, &infop->si_errno);
> + if (!retval)
> + retval = put_user(0, &infop->si_code);
> + if (!retval)
> + retval = put_user(0, &infop->si_pid);
> + if (!retval)
> + retval = put_user(0, &infop->si_uid);
> + if (!retval)
> + retval = put_user(0, &infop->si_status);

Is it really necessary to check the exit code after each put_user?
if (!retval && access_ok(VERIFY_WRITE, infop, sizeof(*infop)))) {
retval = __put_user(0, &infop->si_signo);
retval |= __put_user(0, &infop->si_errno);
retval |= __put_user(0, &infop->si_code);
retval |= __put_user(0, &infop->si_pid);
retval |= __put_user(0, &infop->si_uid);
retval |= __put_user(0, &infop->si_status);
}
is what kernel usually does when filling multiple structure members.

Jakub