From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51970 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751062AbcKIKIm (ORCPT ); Wed, 9 Nov 2016 05:08:42 -0500 Subject: Patch "cgroup: avoid false positive gcc-6 warning" has been added to the 4.4-stable tree To: arnd@arndb.de, gregkh@linuxfoundation.org, tj@kernel.org Cc: , From: Date: Wed, 09 Nov 2016 11:08:47 +0100 Message-ID: <1478686127162186@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled cgroup: avoid false positive gcc-6 warning to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cgroup-avoid-false-positive-gcc-6-warning.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From cfe02a8a973e7e5f66926b8ae38dfce404b19e29 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 15 Mar 2016 00:21:06 +0100 Subject: cgroup: avoid false positive gcc-6 warning From: Arnd Bergmann commit cfe02a8a973e7e5f66926b8ae38dfce404b19e29 upstream. When all subsystems are disabled, gcc notices that cgroup_subsys_enabled_key is a zero-length array and that any access to it must be out of bounds: In file included from ../include/linux/cgroup.h:19:0, from ../kernel/cgroup.c:31: ../kernel/cgroup.c: In function 'cgroup_add_cftypes': ../kernel/cgroup.c:261:53: error: array subscript is above array bounds [-Werror=array-bounds] return static_key_enabled(cgroup_subsys_enabled_key[ssid]); ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~ ../include/linux/jump_label.h:271:40: note: in definition of macro 'static_key_enabled' static_key_count((struct static_key *)x) > 0; \ ^ We should never call the function in this particular case, so this is not a bug. In order to silence the warning, this adds an explicit check for the CGROUP_SUBSYS_COUNT==0 case. Signed-off-by: Arnd Bergmann Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- kernel/cgroup.c | 3 +++ 1 file changed, 3 insertions(+) --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -236,6 +236,9 @@ static int cgroup_addrm_files(struct cgr */ static bool cgroup_ssid_enabled(int ssid) { + if (CGROUP_SUBSYS_COUNT == 0) + return false; + return static_key_enabled(cgroup_subsys_enabled_key[ssid]); } Patches currently in stable-queue which might be from arnd@arndb.de are queue-4.4/drm-exynos-fix-error-handling-in-exynos_drm_subdrv_open.patch queue-4.4/arm-8584-1-floppy-avoid-gcc-6-warning.patch queue-4.4/powerpc-ptrace-fix-out-of-bounds-array-access-warning.patch queue-4.4/cgroup-avoid-false-positive-gcc-6-warning.patch queue-4.4/smc91x-avoid-self-comparison-warning.patch