Date: Fri, 4 Feb 2005 14:39:17 -0800
From: Andrew Morton <akpm@osdl.org>
To: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: bstroesser@fujitsu-siemens.com, roland@redhat.com, jdike@addtoit.com,
       blaisorblade_spam@yahoo.it, user-mode-linux-devel@lists.sourceforge.net,
       linux-kernel@vger.kernel.org
Subject: Re: Race condition in ptrace
Message-Id: <20050204143917.1f9507cb.akpm@osdl.org>
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Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> Bodo Stroesser wrote:
> > Nick Piggin wrote:
> > 
> >> Bodo Stroesser wrote:
> 
> >> I don't see how this could help because AFAIKS, child->saving is only
> >> set and cleared while the runqueue is locked. And the same runqueue lock
> >> is taken by wait_task_inactive.
> >>
> > 
> > Sorry, that not right. There are some routines called by sched(), that 
> > release
> > and reacquire the runqueue lock.
> > 
> 
> Oh yeah, it is the wake_sleeping_dependent / dependent_sleeper crap.
> Sorry, you are right. And that's definitely a bug in sched.c, because
> it breaks wait_task_inactive, as you've rightly observed.
> 
> Andrew, IMO this is another bug to hold 2.6.11 for.

Sure.  I wouldn't consider Bodo's patch to be the one to use though..
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