From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3C756EB64DA for ; Thu, 22 Jun 2023 14:08:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230237AbjFVOIT (ORCPT ); Thu, 22 Jun 2023 10:08:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229995AbjFVOIR (ORCPT ); Thu, 22 Jun 2023 10:08:17 -0400 Received: from omta34.uswest2.a.cloudfilter.net (omta34.uswest2.a.cloudfilter.net [35.89.44.33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BA65AE2 for ; Thu, 22 Jun 2023 07:08:15 -0700 (PDT) Received: from eig-obgw-5003a.ext.cloudfilter.net ([10.0.29.159]) by cmsmtp with ESMTP id BxSmqHbNZfaVXCKytqMSkE; Thu, 22 Jun 2023 14:08:15 +0000 Received: from gator4166.hostgator.com ([108.167.133.22]) by cmsmtp with ESMTPS id CKysqdhZU9GewCKysqO6vk; Thu, 22 Jun 2023 14:08:14 +0000 X-Authority-Analysis: v=2.4 cv=a74jSGeF c=1 sm=1 tr=0 ts=649455ce a=1YbLdUo/zbTtOZ3uB5T3HA==:117 a=WzbPXH4gqzPVN0x6HrNMNA==:17 a=dLZJa+xiwSxG16/P+YVxDGlgEgI=:19 a=IkcTkHD0fZMA:10 a=of4jigFt-DYA:10 a=wYkD_t78qR0A:10 a=VwQbUJbxAAAA:8 a=f5R3gcx-rqYdtmm8484A:9 a=QEXdDO2ut3YA:10 a=AjGcO6oz07-iQ99wixmX:22 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=embeddedor.com; s=default; h=Content-Transfer-Encoding:Content-Type: In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date:Message-ID:Sender :Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=o3nVrYc6RnMxf0e4iXIYtKi5C8Jg0CJJ5aA5IElG1J4=; b=NgA+pmIXcZG44sheyyW+4X1RXY smpeQnJ51qjrJ/tGhVsmFIqY7x6nBKhE8k6xCuSipNQc1IP19DirM4La5M1Ge9T6pbANFk6+/t0B1 M4kqNHjb02rpzZI6hy/+OCv693WiSmAdv7SI4hSMAKhh6LT3laJeSStXoI+jMknLTGdPu0Y6j+k5M u3NY4wbs3bt0hYozTpgWxUOkcZKN6k53nBBJ3279HPdS3HH3D4WbFAfUcDGguMvJZhavp9U1IXX1P 27FMwsTERckNPsUodrrztxoo9JNMj78L+9fXGe3UK2ZaViArNdjSUuqZ/TkhIwyP8BCdYgaWQf1Iy Jm3+xxAg==; Received: from 187-162-21-192.static.axtel.net ([187.162.21.192]:43202 helo=[192.168.15.8]) by gator4166.hostgator.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.95) (envelope-from ) id 1qCKyr-000Aa9-Dy; Thu, 22 Jun 2023 09:08:13 -0500 Message-ID: <0d6377ef-bc34-784a-8694-478d0ade085e@embeddedor.com> Date: Thu, 22 Jun 2023 08:09:03 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH][next] cgroup: Avoid -Wstringop-overflow warnings Content-Language: en-US To: Steven Price , "Gustavo A. R. Silva" , Tejun Heo , Zefan Li , Johannes Weiner Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees Cook References: <726aae97-755d-9806-11d4-2fb21aa93428@arm.com> From: "Gustavo A. R. Silva" In-Reply-To: <726aae97-755d-9806-11d4-2fb21aa93428@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 187.162.21.192 X-Source-L: No X-Exim-ID: 1qCKyr-000Aa9-Dy X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: 187-162-21-192.static.axtel.net ([192.168.15.8]) [187.162.21.192]:43202 X-Source-Auth: gustavo@embeddedor.com X-Email-Count: 3 X-Org: HG=hgshared;ORG=hostgator; X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes X-CMAE-Envelope: MS4xfIcQkW0jDi8w2+NbJ+Trh4cndyQ5RMF8ipreME1Q353xRFrGYN2Hs2utbqNb6AhO+pOrrS8GhP1/QOcNS/1D5Eq+nBjbDOE3J4R5/RDmylz7RF/HmJyl XsJxTLft4sOiVzLae0onBpNK/5OxbXEa5963N54MEI9w8QX6dtHTdZ66vSQoRhzyzPyG3XZ86J4jvwIhow3SKeZbQS1OxynHvi4Bj3rxTujAKf/jM8MT6HA8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! On 6/22/23 04:11, Steven Price wrote: > On 15/06/2023 02:18, Gustavo A. R. Silva wrote: >> Address the following -Wstringop-overflow warnings seen when >> built with ARM architecture and aspeed_g4_defconfig configuration >> (notice that under this configuration CGROUP_SUBSYS_COUNT == 0): >> kernel/cgroup/cgroup.c:1208:16: warning: 'find_existing_css_set' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] >> kernel/cgroup/cgroup.c:1258:15: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] >> kernel/cgroup/cgroup.c:6089:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] >> kernel/cgroup/cgroup.c:6153:18: warning: 'css_set_hash' accessing 4 bytes in a region of size 0 [-Wstringop-overflow=] >> >> These changes are based on commit d20d30ebb199 ("cgroup: Avoid compiler >> warnings with no subsystems"). >> >> Signed-off-by: Gustavo A. R. Silva >> --- >> kernel/cgroup/cgroup.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c >> index cd497b90e11a..1ee76e62eb98 100644 >> --- a/kernel/cgroup/cgroup.c >> +++ b/kernel/cgroup/cgroup.c >> @@ -1200,6 +1200,9 @@ static struct css_set *find_css_set(struct css_set *old_cset, >> unsigned long key; >> int ssid; >> >> + if (!CGROUP_HAS_SUBSYS_CONFIG) >> + return NULL; >> + >> lockdep_assert_held(&cgroup_mutex); >> >> /* First see if we already have a cgroup group that matches >> @@ -6045,6 +6048,9 @@ int __init cgroup_init(void) >> struct cgroup_subsys *ss; >> int ssid; >> >> + if (!CGROUP_HAS_SUBSYS_CONFIG) >> + return -EINVAL; >> + >> BUILD_BUG_ON(CGROUP_SUBSYS_COUNT > 16); >> BUG_ON(cgroup_init_cftypes(NULL, cgroup_base_files)); >> BUG_ON(cgroup_init_cftypes(NULL, cgroup_psi_files)); > > This change (which landed in linux-next) causes a boot failure on my > (arm32) board because the cgroup filesystem isn't created which upsets > systemd: > > [ 11.474767] systemd[1]: Failed to mount tmpfs at /sys/fs/cgroup: No such file or directory > [ 11.489933] systemd[1]: Failed to mount cgroup at /sys/fs/cgroup/systemd: No such file or directory > [!!!!!!] Failed to mount API filesystems. > > Reverting this commit on the head of linux-next gets the board working > again. Thanks for reporting this issue. I'll take a look. -- Gustavo