Re: [PATCH 3/5] Use copy_wait_opts_to_user() in do_wait()

Oleg Nesterov
2009-06-15T16:44:35Z

Damn. I am sorry for the huge delay. Finally I have read this series
carefully.

On 05/11, Vitaly Mayatskikh wrote:
>
> --- a/kernel/exit.c
> +++ b/kernel/exit.c
> @@ -1600,8 +1600,6 @@ end:
> __set_current_state(TASK_RUNNING);
> remove_wait_queue(&current->signal->wait_chldexit,&wait);
> if (wo->wo_info) {
> - struct siginfo __user *infop = wo->wo_info;
> -
> if (retval > 0)
> retval = 0;
> else {
> @@ -1610,18 +1608,7 @@ end:
> * 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);
> + retval = copy_wait_opts_to_user(wo, 0, 0, 0, 0, 0, 0);

This looks wrong.

copy_wait_opts_to_user()->getrusage() will OOPS if ->wo_rusage != NULL,
because we pass p == NULL.

Easy to fix, but I am not sure what is the most clean fix...

Oleg.