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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 4978AC282C4 for ; Tue, 5 Feb 2019 02:55:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 104962081B for ; Tue, 5 Feb 2019 02:55:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EvcnrLBz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727119AbfBECzW (ORCPT ); Mon, 4 Feb 2019 21:55:22 -0500 Received: from mail-pf1-f174.google.com ([209.85.210.174]:38509 "EHLO mail-pf1-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726518AbfBECzW (ORCPT ); Mon, 4 Feb 2019 21:55:22 -0500 Received: by mail-pf1-f174.google.com with SMTP id q1so852133pfi.5 for ; Mon, 04 Feb 2019 18:55:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language:content-transfer-encoding; bh=Kx+jY+MsNDfjNun/LQ2YSUtniOFgDOKuaqAWO/DDE/w=; b=EvcnrLBzU8uKF89/ZXnhGg335n+VI5sI8w1fSfsZJ3601fZrm0zwaL1gydEcwTtseS 7yFx8x2Kn2rsnSIyCTYC2eSXN+jq26MpBV9CSARFoMcvJJ3p8QNIQVkmAvm5WdEB23oU qnDxwlljdoQGx16m/dstEfS5b4sSOPOwav1yLY3Cw8l6ZSDkBKcSUW8pgyllYoKKExCM 51BJ8iXCj5uBi2UkHVh0MGCDrmMi9nS39hkj/QulcL4T+ZZN25vRzrwCwF/fWUx8OpAx KjZvpa5zKO1wPxPZZsqt/6OwQngu55wIIqPT3++Eq8HFyRZtJKle9Pt9d/1EfLhc30OE 0Zaw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=Kx+jY+MsNDfjNun/LQ2YSUtniOFgDOKuaqAWO/DDE/w=; b=XqNm+Bm0IsLhH+ldOe5s4sp1kKVrSqDi8/lP5j4vDGkVdAkVi+Wh8QAqNZXSp9KTde JcuxwJ+xluqb8sGDOkZChlaksROKIgId5PloZRbUeszijfRSaQBLdyq5QNBZ+TOWGEkv 0JWT35shBWDVhbg52rhTDD267YcdbgUS54xhcgKxnXkK3Irds6U4GdWalN2LucMB+i4V GAu5KyyQgQy0PpM6h0aEiLn+YEnPfEkjhzvqfT7tLSrLuoYUAUghoChD/9sg8bBvpk3y BsT0OWdCMC5uYKqt0FjD5RYZ2tIxMc+XVJwZWJ7+lAN/iBdr2XmYM13F+evXn49xJxUp cAQw== X-Gm-Message-State: AHQUAuZkIG8YjGtc7qMVic2lz4KvnrVqbw1ZQ+M28hYRw/4zsFrt+nFI SL5DEupICnR1Ci67qFfWxgOH/PpQ X-Google-Smtp-Source: AHgI3Iaz7EUs5m6xiO4wtZ3SPpKf5jC4+KNb3XymnpsxOXALi2Zcxd8ub6T8DK264wCMXKKXlX+lpw== X-Received: by 2002:a63:fd07:: with SMTP id d7mr2373465pgh.163.1549335321563; Mon, 04 Feb 2019 18:55:21 -0800 (PST) Received: from [172.27.227.2] ([216.129.126.118]) by smtp.googlemail.com with ESMTPSA id d16sm1613425pgj.21.2019.02.04.18.55.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 04 Feb 2019 18:55:20 -0800 (PST) Subject: Re: Compiler warning To: Koen Vandeputte , netdev@vger.kernel.org References: <60f98697-952d-aa39-765f-29736de0c4a2@ncentric.com> From: David Ahern Message-ID: Date: Mon, 4 Feb 2019 18:55:19 -0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <60f98697-952d-aa39-765f-29736de0c4a2@ncentric.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/4/19 3:43 AM, Koen Vandeputte wrote: > Hi All, > > I'm seeing following compiler warning during kernel compilation > (5.0-rc5  and  4.14.96): > > > net/core/dev.c: In function 'validate_xmit_skb_list': > net/core/dev.c:3405:15: warning: 'tail' may be used uninitialized in > this function [-Wmaybe-uninitialized] >     tail->next = skb; >     ~~~~~~~~~~~^~~~~ > > > Source shows this: > > https://elixir.bootlin.com/linux/v5.0-rc5/source/net/core/dev.c#L3387 > > Looks like "tail" can get deferenced while it indeed doesn't get > initialized? Kind regards, Koen > same with this one - false positive. head is initialized to NULL. tail is set on the first pass through the loop. What compiler / version is this?