Re: [PATCH RT 3/4] net: netfilter: Serialize xt_write_recseq sections on RT

[Thomas Gleixner <tglx@linutronix.de>]

On Wed, 31 Oct 2012, Peter LaDow wrote:
> On Tue, Oct 30, 2012 at 5:33 PM, Steven Rostedt <rostedt@goodmis.org> wrote:
> > From: Thomas Gleixner <tglx@linutronix.de>
> >
> > The netfilter code relies only on the implicit semantics of
> > local_bh_disable() for serializing wt_write_recseq sections. RT breaks
> > that and needs explicit serialization here.
> >
> > Reported-by: Peter LaDow <petela@gocougs.wsu.edu>
> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 
> > diff --git a/include/linux/locallock.h b/include/linux/locallock.h
> > index f1804a3..a5eea5d 100644
> 
> > diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
> > index 32cddf7..bed90da2 100644
> 
> > diff --git a/net/netfilter/core.c b/net/netfilter/core.c
> > index 899b71c..5db16ea 100644
> 
> I'm trying these out right now.  We've applied these patches to
> 3.0.36-rt58 (rather than pull in the full 3.0.48-rt72 -- too much risk
> for us right now to do a full kernel change).  I am setting up a

Cough. You are missing a boat load of crucial fixes. There is a damned
good reason why 3.0.stable got 12 updates and the -rt version 14.

Your risk assessment is definitley interesting.

Thanks,

	tglx