From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761471AbcLRWjm (ORCPT ); Sun, 18 Dec 2016 17:39:42 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:54492 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754489AbcLRWjl (ORCPT ); Sun, 18 Dec 2016 17:39:41 -0500 Date: Sun, 18 Dec 2016 14:39:40 -0800 From: Darren Hart To: Peter Zijlstra Cc: tglx@linutronix.de, mingo@kernel.org, juri.lelli@arm.com, rostedt@goodmis.org, xlpang@redhat.com, bigeasy@linutronix.de, linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, jdesfossez@efficios.com, bristot@redhat.com Subject: Re: [PATCH -v4 00/10] FUTEX_UNLOCK_PI wobbles Message-ID: <20161218223940.GA67477@f23x64.localdomain> References: <20161213083638.938898295@infradead.org> <20161216233140.GC62123@f23x64.localdomain> <20161217135214.GY3107@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161217135214.GY3107@twins.programming.kicks-ass.net> User-Agent: Mutt/1.7.1 (2016-10-04) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Dec 17, 2016 at 02:52:14PM +0100, Peter Zijlstra wrote: > On Fri, Dec 16, 2016 at 03:31:40PM -0800, Darren Hart wrote: > > On Tue, Dec 13, 2016 at 09:36:38AM +0100, Peter Zijlstra wrote: > > > That way, when we drop hb->lock to wait, futex and rt_mutex wait state is > > > consistent. > > > > > > > > > In any case, it passes our inadequate testing. > > > > It passed my CI tools/testing/selftests/futex/functional/run.sh. Did you also > > happen to run a fuzz tester? > > I did not. I'm not sure how good trinity is at poking holes in futexes. > I would love a domain specific fuzzer for futex, but I suspect it would > end up being me writing it :-( > Trinity had some futex awareness and found several issues in the past, I can't say how likely it is to find more. I haven't tried ... syzcaller? yet. I had set out to do this in the futextest suite, which I later merged into kselftests, but I scrapped the fuzz testing, deferring to trinity. Perhaps that is a project we should resurrect. -- Darren Hart Intel Open Source Technology Center