From: "Paul E. McKenney" <paulmck@us.ibm.com>
To: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Ingo Molnar <mingo@elte.hu>, Dipankar Sarma <dipankar@in.ibm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC,PATCH] Use RCU to protect tasklist for unicast signals
Date: Fri, 12 Aug 2005 08:42:52 -0700 [thread overview]
Message-ID: <20050812154252.GB1297@us.ibm.com> (raw)
In-Reply-To: <42FC6305.E7A00C0A@tv-sign.ru>
On Fri, Aug 12, 2005 at 12:51:17PM +0400, Oleg Nesterov wrote:
> Paul E. McKenney wrote:
> >
> > --- linux-2.6.13-rc4-realtime-preempt-V0.7.53-01/fs/exec.c 2005-08-11 11:44:55.000000000 -0700
> > +++ linux-2.6.13-rc4-realtime-preempt-V0.7.53-01-tasklistRCU/fs/exec.c 2005-08-11 12:26:45.000000000 -0700
> > [ ... snip ... ]
> > @@ -785,11 +787,13 @@ no_thread_group:
> > recalc_sigpending();
> >
> > + oldsighand->deleted = 1;
> > + oldsighand->successor = newsighand;
>
> I don't think this is correct.
>
> This ->oldsighand can be shared with another CLONE_SIGHAND
> process and will not be deleted, just unshared.
>
> When the signal is sent to that process we must use ->oldsighand
> for locking, not the oldsighand->successor == newsighand.
Hmmm... Sounds like I mostly managed to dig myself in deeper here.
Back to the drawing board...
Thanx, Paul
next prev parent reply other threads:[~2005-08-12 15:42 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-11 12:16 [RFC,PATCH] Use RCU to protect tasklist for unicast signals Oleg Nesterov
2005-08-11 15:20 ` Paul E. McKenney
2005-08-12 1:56 ` Paul E. McKenney
2005-08-12 8:51 ` Oleg Nesterov
2005-08-12 15:42 ` Paul E. McKenney [this message]
2005-08-15 17:44 ` Paul E. McKenney
2005-08-16 8:14 ` Ingo Molnar
2005-08-16 11:56 ` Oleg Nesterov
2005-08-16 17:07 ` Paul E. McKenney
2005-08-17 1:48 ` Paul E. McKenney
2005-08-17 6:35 ` Ingo Molnar
2005-08-17 14:35 ` Oleg Nesterov
2005-08-17 21:19 ` Paul E. McKenney
2005-08-18 11:48 ` Oleg Nesterov
2005-08-19 1:29 ` Paul E. McKenney
2005-08-19 13:27 ` Oleg Nesterov
2005-08-19 18:34 ` Paul E. McKenney
2005-08-18 12:24 ` Oleg Nesterov
-- strict thread matches above, loose matches on Subject: below --
2005-08-10 17:11 Paul E. McKenney
2005-08-11 9:56 ` Ingo Molnar
2005-08-11 14:14 ` Paul E. McKenney
2005-08-12 2:00 ` Lee Revell
2005-08-12 6:36 ` Ingo Molnar
2005-08-12 20:57 ` Paul E. McKenney
2005-08-11 17:14 ` Christoph Hellwig
2005-08-11 17:56 ` Paul E. McKenney
2005-08-11 18:00 ` Dipankar Sarma
2005-08-11 18:12 ` Dipankar Sarma
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