From patchwork Mon May 18 17:36:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 225881 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A2FC4C433DF for ; Mon, 18 May 2020 17:39:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86DCA207C4 for ; Mon, 18 May 2020 17:39:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823580; bh=6izUGOAV4EOf7h5UH8myKsEBB6IYFMoy2mjCJTRsoWc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IKooF4Ir4XhwWuJz5qGTDDnxtjTpFN5M+jn/UWgwFxwLi2mEF108bv/Bpkpr/jO1I AhkF/7znoW2u6wesmZpw1WvQkAG8Plki6zbFPXrQgiuh+d6jPzN9qfHfKpmBPBHoVd YrjmHKrhfC2NsmCrj6MXInJBVhgUVfFl+ggfWN8U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728833AbgERRjj (ORCPT ); Mon, 18 May 2020 13:39:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:34470 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728851AbgERRjj (ORCPT ); Mon, 18 May 2020 13:39:39 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id F0F2920829; Mon, 18 May 2020 17:39:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823578; bh=6izUGOAV4EOf7h5UH8myKsEBB6IYFMoy2mjCJTRsoWc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XWUQIfycvgPIAuPXYWO5nwyQK9oXmsm2+Sl2wvLF2mVnqK8MC/mmhMnFki0piP+zz 23CTPa+o1BQWbcY0mGJV66NhjexsI99nmNtlpfC2YoA7rRMCCoqEoKilpL+pFLrMYU Qx4KEsjYkul1fThB4dfKAQnpsBV9pxJqHegbGbns= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Arnd Bergmann , Neil Horman , "David S. Miller" , Sasha Levin Subject: [PATCH 4.4 38/86] drop_monitor: work around gcc-10 stringop-overflow warning Date: Mon, 18 May 2020 19:36:09 +0200 Message-Id: <20200518173458.159893865@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173450.254571947@linuxfoundation.org> References: <20200518173450.254571947@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Arnd Bergmann [ Upstream commit dc30b4059f6e2abf3712ab537c8718562b21c45d ] The current gcc-10 snapshot produces a false-positive warning: net/core/drop_monitor.c: In function 'trace_drop_common.constprop': cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] In file included from net/core/drop_monitor.c:23: include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here 36 | __u32 entries; | ^~~~~~~ I reported this in the gcc bugzilla, but in case it does not get fixed in the release, work around it by using a temporary variable. Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol") Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881 Signed-off-by: Arnd Bergmann Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/core/drop_monitor.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index a2270188b8649..9bcc6fdade3eb 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -159,6 +159,7 @@ static void sched_send_work(unsigned long _data) static void trace_drop_common(struct sk_buff *skb, void *location) { struct net_dm_alert_msg *msg; + struct net_dm_drop_point *point; struct nlmsghdr *nlh; struct nlattr *nla; int i; @@ -177,11 +178,13 @@ static void trace_drop_common(struct sk_buff *skb, void *location) nlh = (struct nlmsghdr *)dskb->data; nla = genlmsg_data(nlmsg_data(nlh)); msg = nla_data(nla); + point = msg->points; for (i = 0; i < msg->entries; i++) { - if (!memcmp(&location, msg->points[i].pc, sizeof(void *))) { - msg->points[i].count++; + if (!memcmp(&location, &point->pc, sizeof(void *))) { + point->count++; goto out; } + point++; } if (msg->entries == dm_hit_limit) goto out; @@ -190,8 +193,8 @@ static void trace_drop_common(struct sk_buff *skb, void *location) */ __nla_reserve_nohdr(dskb, sizeof(struct net_dm_drop_point)); nla->nla_len += NLA_ALIGN(sizeof(struct net_dm_drop_point)); - memcpy(msg->points[msg->entries].pc, &location, sizeof(void *)); - msg->points[msg->entries].count = 1; + memcpy(point->pc, &location, sizeof(void *)); + point->count = 1; msg->entries++; if (!timer_pending(&data->send_timer)) {