From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753647AbcEBLG5 (ORCPT ); Mon, 2 May 2016 07:06:57 -0400 Received: from e33.co.us.ibm.com ([32.97.110.151]:56094 "EHLO e33.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753759AbcEBLGs (ORCPT ); Mon, 2 May 2016 07:06:48 -0400 X-IBM-Helo: d03dlp02.boulder.ibm.com X-IBM-MailFrom: paulmck@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org;linux-next@vger.kernel.org Date: Mon, 2 May 2016 04:06:45 -0700 From: "Paul E. McKenney" To: Stephen Rothwell Cc: linux-next@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig Subject: Re: linux-next: build failure after merge of the rcu tree Message-ID: <20160502110645.GS3686@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20160502143736.631f2a44@canb.auug.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160502143736.631f2a44@canb.auug.org.au> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16050211-0009-0000-0000-0000281A0A9E Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 02, 2016 at 02:37:36PM +1000, Stephen Rothwell wrote: > Hi Paul, > > After merging the rcu tree, today's linux-next build (x86_64 allmodconfig) > failed like this: > > arch/x86/kvm/vmx.c: In function 'vmx_init': > arch/x86/kvm/vmx.c:11026:2: error: function '_r_a_p__v' is initialized like a variable > rcu_assign_pointer(crash_vmclear_loaded_vmcss, > ^ > In file included from include/linux/rbtree.h:34:0, > from include/linux/mm_types.h:9, > from arch/x86/kvm/irq.h:25, > from arch/x86/kvm/vmx.c:19: > include/linux/rcupdate.h:657:45: warning: the comparison will always evaluate as 'false' for the address of '_r_a_p__v' will never be NULL [-Waddress] > if (__builtin_constant_p(v) && (_r_a_p__v) == NULL) \ > ^ > arch/x86/kvm/vmx.c:11026:2: note: in expansion of macro 'rcu_assign_pointer' > rcu_assign_pointer(crash_vmclear_loaded_vmcss, > ^ > include/linux/rcupdate.h:655:12: error: nested function '_r_a_p__v' declared but never defined > typeof(v) _r_a_p__v = (v); \ > ^ > arch/x86/kvm/vmx.c:11026:2: note: in expansion of macro 'rcu_assign_pointer' > rcu_assign_pointer(crash_vmclear_loaded_vmcss, > ^ > > Caused by commit > > 16d7afcaa530 ("rcu: No ordering for rcu_assign_pointer() of NULL") > > I have reverted that commit for today. Too much fun when rcu_assign_pointer() is invoked on a pointer to a function... Sorry for the hassle! Thanx, Paul