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* wait_task_zombie plus WNOWAIT question
@ 2009-07-01 13:41 Vitaly Mayatskikh
  2009-07-01 13:55 ` Oleg Nesterov
  0 siblings, 1 reply; 3+ messages in thread
From: Vitaly Mayatskikh @ 2009-07-01 13:41 UTC (permalink / raw)
  To: Roland McGrath; +Cc: Oleg Nesterov, linux-kernel

Hi!

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 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?

Thanks!
-- 
wbr, Vitaly

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: wait_task_zombie plus WNOWAIT question
  2009-07-01 13:41 wait_task_zombie plus WNOWAIT question Vitaly Mayatskikh
@ 2009-07-01 13:55 ` Oleg Nesterov
  2009-07-01 14:10   ` Vitaly Mayatskikh
  0 siblings, 1 reply; 3+ messages in thread
From: Oleg Nesterov @ 2009-07-01 13:55 UTC (permalink / raw)
  To: Vitaly Mayatskikh; +Cc: Roland McGrath, linux-kernel

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.

Oleg.


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: wait_task_zombie plus WNOWAIT question
  2009-07-01 13:55 ` Oleg Nesterov
@ 2009-07-01 14:10   ` Vitaly Mayatskikh
  0 siblings, 0 replies; 3+ messages in thread
From: Vitaly Mayatskikh @ 2009-07-01 14:10 UTC (permalink / raw)
  To: Oleg Nesterov; +Cc: Vitaly Mayatskikh, Roland McGrath, linux-kernel

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

^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2009-07-01 14:10 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-07-01 13:41 wait_task_zombie plus WNOWAIT question Vitaly Mayatskikh
2009-07-01 13:55 ` Oleg Nesterov
2009-07-01 14:10   ` Vitaly Mayatskikh

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