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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 4E3CDC32750 for ; Wed, 14 Aug 2019 02:38:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C55C2084F for ; Wed, 14 Aug 2019 02:38:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565750302; bh=yzdK0cpATKfDgE266QK3LkS15A5pMnjiRaPV3/oLKK0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qcBAFEZ7r/yEr0mzGUAW0MIgpSPjLnasqdTWB4smDfyBAy6AspCZ9Jpq6BSjoNOf5 0QxqloCca+86p2ZWGUAAZoyTEhqnLDa0FVDfYc0jWvaSYnfN/yWJzpSCHvl5MAixIB JpowBzKS/AtkyPzEjC81D0Lf5z35LT9qaiIpwu7Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727120AbfHNCM2 (ORCPT ); Tue, 13 Aug 2019 22:12:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:44534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727049AbfHNCMZ (ORCPT ); Tue, 13 Aug 2019 22:12:25 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B143E208C2; Wed, 14 Aug 2019 02:12:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565748744; bh=yzdK0cpATKfDgE266QK3LkS15A5pMnjiRaPV3/oLKK0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HIs12VncSQZzDwaziPUuf8ieOi2wuBWDLiq6XiNX8+AM+c4IAQi9vhD5IuQmokLC7 pjPcKcvXfZgGCubr2yWiGIveKGITN4CJI7vj50JELfypyJQannTHRtaaoJxcoWAmau 5evEpKglcvt91d/AnMr6IbeMYG2+qDxvzX6mWyiY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Andrii Nakryiko , Magnus Karlsson , Song Liu , Alexei Starovoitov , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.2 042/123] libbpf: silence GCC8 warning about string truncation Date: Tue, 13 Aug 2019 22:09:26 -0400 Message-Id: <20190814021047.14828-42-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190814021047.14828-1-sashal@kernel.org> References: <20190814021047.14828-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Andrii Nakryiko [ 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