From patchwork Thu Apr 21 00:39:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 12820963 X-Patchwork-Delegate: bpf@iogearbox.net 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 E1815C433F5 for ; Thu, 21 Apr 2022 00:40:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383548AbiDUAm4 (ORCPT ); Wed, 20 Apr 2022 20:42:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1383552AbiDUAmw (ORCPT ); Wed, 20 Apr 2022 20:42:52 -0400 Received: from mail-40131.protonmail.ch (mail-40131.protonmail.ch [185.70.40.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42B291BEBF for ; Wed, 20 Apr 2022 17:40:04 -0700 (PDT) Date: Thu, 21 Apr 2022 00:39:57 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail2; t=1650501602; bh=W0VffryUE5RZwuv08QCVM2IU2VidejFL9tGRVW8qxIU=; h=Date:To:From:Cc:Reply-To:Subject:Message-ID:In-Reply-To: References:Feedback-ID:From:To:Cc:Date:Subject:Reply-To: Feedback-ID:Message-ID; b=ZmwSroo+f/5b/WG1HKGylRZynSpIQ7KwWJXsPB35AcEjjQWgWLGzrrLTKHiJQ7mYT wzphf4JosMH0oJ6OOq5QI+pEO6tAU/smfTxKKI2n7mFUlmEEg+CD8SOOGxwCfdZKzP p1rBaXkzYRrAwc0OFrTOIK8SLRaPd34JorLslZzs+kVaRX1fiL5w6jDgHPQ/Jk364F dTC0WyV45BxGoQjD985X18M+2afDUl4jpRq9H9oYPr0jX/TzoCzNeL369xQanMyqb6 ck3tLF/yLpqjIn+RXHbFNveiB8nbS3dmPKyfMidq4O/TjC/jA+t97ZiJMjx5q8IKuj WEOC87ZPC22yA== To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko From: Alexander Lobakin Cc: Alexander Lobakin , Maciej Fijalkowski , Song Liu , Kumar Kartikeya Dwivedi , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Reply-To: Alexander Lobakin Subject: [PATCH v2 bpf 11/11] samples/bpf: xdpsock: fix -Wmaybe-uninitialized Message-ID: <20220421003152.339542-12-alobakin@pm.me> In-Reply-To: <20220421003152.339542-1-alobakin@pm.me> References: <20220421003152.339542-1-alobakin@pm.me> Feedback-ID: 22809121:user:proton MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Fix two sort-of-false-positives in the xdpsock userspace part: samples/bpf/xdpsock_user.c: In function 'main': samples/bpf/xdpsock_user.c:1531:47: warning: 'tv_usec' may be used uninitialized in this function [-Wmaybe-uninitialized] 1531 | pktgen_hdr->tv_usec = htonl(tv_usec); | ^~~~~~~~~~~~~~ samples/bpf/xdpsock_user.c:1500:26: note: 'tv_usec' was declared here 1500 | u32 idx, tv_sec, tv_usec; | ^~~~~~~ samples/bpf/xdpsock_user.c:1530:46: warning: 'tv_sec' may be used uninitialized in this function [-Wmaybe-uninitialized] 1530 | pktgen_hdr->tv_sec = htonl(tv_sec); | ^~~~~~~~~~~~~ samples/bpf/xdpsock_user.c:1500:18: note: 'tv_sec' was declared here 1500 | u32 idx, tv_sec, tv_usec; | ^~~~~~ Both variables are always initialized when @opt_tstamp == true and they're being used also only when @opt_tstamp == true. However, that variable comes from the BSS and is being toggled from another function. They can't be executed simultaneously to actually trigger undefined behaviour, but purely technically it is a correct warning. Just initialize them with zeroes. Fixes: eb68db45b747 ("samples/bpf: xdpsock: Add timestamp for Tx-only operation") Acked-by: Maciej Fijalkowski Acked-by: Song Liu Signed-off-by: Alexander Lobakin --- samples/bpf/xdpsock_user.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.36.0 diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 9747d47a0a8f..a6d8291c8b38 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -1497,7 +1497,7 @@ static void rx_drop_all(void) static int tx_only(struct xsk_socket_info *xsk, u32 *frame_nb, int batch_size, unsigned long tx_ns) { - u32 idx, tv_sec, tv_usec; + u32 idx, tv_sec = 0, tv_usec = 0; unsigned int i; while (xsk_ring_prod__reserve(&xsk->tx, batch_size, &idx) <