From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753760AbdCHQVK (ORCPT ); Wed, 8 Mar 2017 11:21:10 -0500 Received: from mail.kernel.org ([198.145.29.136]:53074 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752239AbdCHQVH (ORCPT ); Wed, 8 Mar 2017 11:21:07 -0500 Date: Wed, 8 Mar 2017 11:20:59 -0500 From: Steven Rostedt To: Sebastian Andrzej Siewior Cc: Peter Zijlstra , tglx@linutronix.de, mingo@kernel.org, juri.lelli@arm.com, xlpang@redhat.com, linux-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, jdesfossez@efficios.com, bristot@redhat.com, dvhart@infradead.org Subject: Re: [PATCH] futex: move debug_rt_mutex_free_waiter() further down Message-ID: <20170308112059.64e06683@gandalf.local.home> In-Reply-To: <20170308152901.kumylhi7l3hescxd@linutronix.de> References: <20170304092717.762954142@infradead.org> <20170304093559.546712677@infradead.org> <20170308152901.kumylhi7l3hescxd@linutronix.de> X-Mailer: Claws Mail 3.14.0 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 8 Mar 2017 16:29:02 +0100 Sebastian Andrzej Siewior wrote: > Without this, futex_requeue_pi_signal_restart will trigger > > |kernel BUG at locking/rtmutex_common.h:55! > |Call Trace: > | rt_mutex_cleanup_proxy_lock+0x54/0x90 > | futex_wait_requeue_pi.constprop.21+0x387/0x4d0 > | do_futex+0x289/0xbf0 > |RIP: remove_waiter+0x157/0x170 RSP: ffffc90000e0fbe0 > > with BUG 2222222222222222 != pointer once this patch is applied. This sentence makes no sense. It's a no-sensetence ;-) -- Steve > > Signed-off-by: Sebastian Andrzej Siewior > --- > kernel/futex.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/futex.c b/kernel/futex.c > index 00ec4a01d3f5..73abfe0da4d0 100644 > --- a/kernel/futex.c > +++ b/kernel/futex.c > @@ -3046,11 +3046,11 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags, > WARN_ON(!q.pi_state); > pi_mutex = &q.pi_state->pi_mutex; > ret = rt_mutex_wait_proxy_lock(pi_mutex, to, &rt_waiter); > - debug_rt_mutex_free_waiter(&rt_waiter); > > spin_lock(q.lock_ptr); > if (ret && !rt_mutex_cleanup_proxy_lock(pi_mutex, &rt_waiter)) > ret = 0; > + debug_rt_mutex_free_waiter(&rt_waiter); > > /* > * Fixup the pi_state owner and possibly acquire the lock if we