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 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,URIBL_BLOCKED,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 2E79DC3A5A3 for ; Tue, 27 Aug 2019 08:00:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 019D82186A for ; Tue, 27 Aug 2019 08:00:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566892858; bh=EunKMO7NaZsk1SXtNvSwvp1m/3+ajkQvwMfGkrVaCYs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=XoCtmW9EQBvPobw5345OB8+i2aDgz/o2rrSMYg2ZSjBx89SGVoQIlhisZ+QCOcfeF oF9NqVRt3ZzYzpm9UK2No/7AvIe5uIn6t2R7XHWqmhp3vVEr9izqLC9+90zZx2sXrJ +m8mXeQCRlMM5W8ny5ltdKppgUAg3+bJHY2/OR+Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731625AbfH0IAz (ORCPT ); Tue, 27 Aug 2019 04:00:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:56394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730495AbfH0IAz (ORCPT ); Tue, 27 Aug 2019 04:00:55 -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 DD729206BA; Tue, 27 Aug 2019 08:00:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566892854; bh=EunKMO7NaZsk1SXtNvSwvp1m/3+ajkQvwMfGkrVaCYs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gGRn7JgR/QPFMdUeveu7qQAVZn4Lth3Jyluy/2BtpnWtbKK0Zn3Mq+iSdO0rjUlNY 5TJxu99HQIKnK3mCshrM0klkcVnw3OSw9qni+lVJrpoo6FAR44/XM2xEPBuH52OCES sdEgevEjU4fuTXbd/8FciGWal7ICOsu2X0+HWX3g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Magnus Karlsson , Andrii Nakryiko , Song Liu , Alexei Starovoitov , Sasha Levin Subject: [PATCH 5.2 037/162] libbpf: silence GCC8 warning about string truncation Date: Tue, 27 Aug 2019 09:49:25 +0200 Message-Id: <20190827072739.562169335@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190827072738.093683223@linuxfoundation.org> References: <20190827072738.093683223@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit cb8ffde5694ae5fffb456eae932aac442aa3a207 ] Despite a proper NULL-termination after strncpy(..., ..., IFNAMSIZ - 1), GCC8 still complains about *expected* string truncation: xsk.c:330:2: error: 'strncpy' output may be truncated copying 15 bytes from a string of length 15 [-Werror=stringop-truncation] strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1); This patch gets rid of the issue altogether by using memcpy instead. There is no performance regression, as strncpy will still copy and fill all of the bytes anyway. v1->v2: - rebase against bpf tree. Cc: Magnus Karlsson Signed-off-by: Andrii Nakryiko Acked-by: Magnus Karlsson Acked-by: Song Liu Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- tools/lib/bpf/xsk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c index 8e03b65830da0..fa948c5445ecf 100644 --- a/tools/lib/bpf/xsk.c +++ b/tools/lib/bpf/xsk.c @@ -336,7 +336,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk) return -errno; ifr.ifr_data = (void *)&channels; - strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1); + memcpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1); ifr.ifr_name[IFNAMSIZ - 1] = '\0'; err = ioctl(fd, SIOCETHTOOL, &ifr); if (err && errno != EOPNOTSUPP) { @@ -561,7 +561,7 @@ int xsk_socket__create(struct xsk_socket **xsk_ptr, const char *ifname, err = -errno; goto out_socket; } - strncpy(xsk->ifname, ifname, IFNAMSIZ - 1); + memcpy(xsk->ifname, ifname, IFNAMSIZ - 1); xsk->ifname[IFNAMSIZ - 1] = '\0'; err = xsk_set_xdp_socket_config(&xsk->config, usr_config); -- 2.20.1