From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sun, 05 Jun 2016 23:57:30 +0200 (CEST) Received: from mail.linuxfoundation.org ([140.211.169.12]:60497 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27042484AbcFEVxEfOKIp (ORCPT ); Sun, 5 Jun 2016 23:53:04 +0200 Received: from localhost (c-50-170-35-168.hsd1.wa.comcast.net [50.170.35.168]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id AA4D44D3; Sun, 5 Jun 2016 21:52:57 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Maciej W. Rozycki" , James Hogan , Tejun Heo , linux-mips@linux-mips.org, Ralf Baechle Subject: [PATCH 4.6 026/121] MIPS: VDSO: Build with `-fno-strict-aliasing Date: Sun, 5 Jun 2016 14:42:58 -0700 Message-Id: <20160605214418.508652766@linuxfoundation.org> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160605214417.708509043@linuxfoundation.org> References: <20160605214417.708509043@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 53851 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: gregkh@linuxfoundation.org Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maciej W. Rozycki commit 94cc36b84acc29f543b48bc5ed786011b112a666 upstream. Avoid an aliasing issue causing a build error in VDSO: In file included from include/linux/srcu.h:34:0, from include/linux/notifier.h:15, from ./arch/mips/include/asm/uprobes.h:9, from include/linux/uprobes.h:61, from include/linux/mm_types.h:13, from ./arch/mips/include/asm/vdso.h:14, from arch/mips/vdso/vdso.h:27, from arch/mips/vdso/gettimeofday.c:11: include/linux/workqueue.h: In function 'work_static': include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing] return *work_data_bits(work) & WORK_STRUCT_STATIC; ^ cc1: all warnings being treated as errors make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1 with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0. Include `-fno-strict-aliasing' along with compiler options used, as required for kernel code, fixing a problem present since the introduction of VDSO with commit ebb5e78cc634 ("MIPS: Initial implementation of a VDSO"). Thanks to Tejun for diagnosing this properly! Signed-off-by: Maciej W. Rozycki Reviewed-by: James Hogan Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO") Cc: Tejun Heo Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13357/ Signed-off-by: Ralf Baechle Signed-off-by: Greg Kroah-Hartman --- arch/mips/vdso/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -9,7 +9,8 @@ ccflags-vdso := \ $(filter -march=%,$(KBUILD_CFLAGS)) cflags-vdso := $(ccflags-vdso) \ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ - -O2 -g -fPIC -fno-common -fno-builtin -G 0 -DDISABLE_BRANCH_PROFILING \ + -O2 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ + -DDISABLE_BRANCH_PROFILING \ $(call cc-option, -fno-stack-protector) aflags-vdso := $(ccflags-vdso) \ $(filter -I%,$(KBUILD_CFLAGS)) \