Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755992Ab3GCR7L (ORCPT ); Wed, 3 Jul 2013 13:59:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:63115 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753358Ab3GCR7J (ORCPT ); Wed, 3 Jul 2013 13:59:09 -0400 Date: Wed, 3 Jul 2013 19:54:20 +0200 From: Oleg Nesterov To: Masami Hiramatsu Cc: Steven Rostedt , "zhangwei(Jovi)" , Jiri Olsa , Peter Zijlstra , Arnaldo Carvalho de Melo , Srikar Dronamraju , Frederic Weisbecker , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: PATCH? trace_remove_event_call() should fail if call is active Message-ID: <20130703175420.GA25668@redhat.com> References: <51CCF8BA.4030601@hitachi.com> <20130628180946.GA30838@redhat.com> <51D16E1D.5040904@hitachi.com> <20130702190037.GA6289@redhat.com> <20130702193425.GA8813@redhat.com> <1372799087.22688.58.camel@gandalf.local.home> <20130702213808.GA24757@redhat.com> <20130702222359.GA27629@redhat.com> <51D38F8D.3010708@hitachi.com> <20130703172029.GA14309@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130703172029.GA14309@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 797 Lines: 24 On 07/03, Oleg Nesterov wrote: > > IOW. So far _I think_ we just need the additional changes in > trace_remove_event_call() if it succeeds (with the patch I sent) > to prevent the races like above, but I didn't even try to think > about this problem. And I guess greatly underestimated the problem(s). When I look at this code now, it seems that, say, event_enable_write() will use the already freed ftrace_event_file in this case. Still I think this is another (although closely related) problem. > Or I missed your point completely? Yes? Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/