Re: wait_task_zombie plus WNOWAIT question

From: Vitaly Mayatskikh
Date: Wed Jul 01 2009 - 10:10:27 EST


At Wed, 1 Jul 2009 15:55:44 +0200, Oleg Nesterov wrote:
>
> On 07/01, Vitaly Mayatskikh wrote:
> >
> > I'm working on (sigh) next version of wait_task_* cleanups and stuck
> > in wait_task_zombie. I'm trying to move put_user(stat, wo->wo_stat)
> > code from all wait_task_* functions to common place, but
> > wait_task_zombie does not fill wo_stat if WNOWAIT flag is set
>
> Only waitid() can use WNOWAIT, and in this case ->wo_stat == NULL.
>
> > and does
> > it w/o that flag. Is it done so by design, or I can make
> > user-visible change and add put_user in WNOWAIT path?
>
> Just check do not do put_user(->wo_stat) if it is NULL in do_wait
> pathes.

Got it! Thanks, Oleg!

--
wbr, Vitaly
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