From patchwork Thu Jun 15 01:18:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 13280604 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 478EFEB64D8 for ; Thu, 15 Jun 2023 01:17:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230144AbjFOBR3 (ORCPT ); Wed, 14 Jun 2023 21:17:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35578 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229558AbjFOBR1 (ORCPT ); Wed, 14 Jun 2023 21:17:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A3671FD2; Wed, 14 Jun 2023 18:17:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2DC8161200; Thu, 15 Jun 2023 01:17:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B5D52C433C0; Thu, 15 Jun 2023 01:17:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1686791845; bh=jC/V/5wTuDMjSNiSOnA5excD/Pg4jzWuQwRXLi7lZ5Q=; h=Date:From:To:Cc:Subject:From; b=LNn3r6SsDlIceMsugdzXzyHk9WrMjwzuxupyyplrVHyioNpMJdpql/gLeE+cky74M 7/gIN433a9Az+BryjDhdebV9l6Mnw4rB9+iqI6K5ce3PdjuOyjyiwgS3o4L1jcdmQY t9PY3TpynCOtMjyn4mXp6Wga7IIu/2AZoBsp29aMD6JYTeKrrQppEc0MFMTKtgNwMF krwRXUZxh2Vchb79SSKMEvvLrj7xm3Q1Tb5PktEXXLDaadwmoVq5AWvQv4qwKOV4hQ Rs0JFIB02Mjw2n30gUblEh4OxBCw19+eCBmlKcuJ9iIvOLsYjFdW3V8a5voebM/9Ed mRzHWmC4lfCxA== Date: Wed, 14 Jun 2023 19:18:22 -0600 From: "Gustavo A. R. Silva" To: Tejun Heo , Zefan Li , Johannes Weiner Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] cgroup: Avoid -Wstringop-overflow warnings Message-ID: MIME-Version: 1.0 Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org 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 Reviewed-by: Kees Cook --- 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));