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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,USER_AGENT_MUTT 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 0AB0BC43381 for ; Fri, 22 Mar 2019 16:12:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE03D21916 for ; Fri, 22 Mar 2019 16:12:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TbUJU9dx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729570AbfCVQMu (ORCPT ); Fri, 22 Mar 2019 12:12:50 -0400 Received: from mail-ed1-f65.google.com ([209.85.208.65]:43153 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727169AbfCVQMu (ORCPT ); Fri, 22 Mar 2019 12:12:50 -0400 Received: by mail-ed1-f65.google.com with SMTP id d26so2123285ede.10; Fri, 22 Mar 2019 09:12:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=rNbiROqocIMhe+r4/JZLDDMawn+rRistlEcQ+uTaB7E=; b=TbUJU9dxWeLrnAKFEXRasRmF2hoVCbmrFFAm5vTT+Rh/V+PMd12zifqF71yQPCORiV So8IWVF035URyJms9oKjffyheTwsOVV8jUCYbkUgokbcD+kl/BTEH6eUvRWi5CDbf9S6 7tiICm9FRMpojuX4br0yOE0SYHfFuXvrzAHR0OzvWCMp7cmCvhbo7KsZz60xSQyrU3DA 0kRGst1708o5Auv4JcULzQgSCMkcerg82ZEpi60eu1mMfT/4ctSKZSRuTq69vyQ0deQL Yg7rXhP5gR1xgSsz60UbgJLcHfTWYkeklR/ZD+LKXwSJbXBmX3o7MNbwNZFnAkxIK5/J ahpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=rNbiROqocIMhe+r4/JZLDDMawn+rRistlEcQ+uTaB7E=; b=LaG4XxIbj+WVmk83cEmOgpozcEBNWViaFr1JfYctLNMQwBsYm1TpLvuxXN+UjDgpfA 5e4bp3z4fQhHKPKHiY/4nDFxIQ2OPLojeMoY0SitMG8pyLYfmcgHo/fKhTRhi2wUJi0t LmV0gqmPrdGl/YJ8v1M7D6SXpGtOBllL+s+CdqPQCvSqNjWJJld04udYVGwEwbNzqMSO Rv9pn/inpyoXxV7cw6iQhRXG+y2zfVO3Sn7QaY/WFPAoMhIZA838s3SLPJw7Ate3Si6Q urjbJfJj20OtiVdG5DD09hlIcZDQgAVdnC37wFEqgwqnoaGSl1B9r7uW10cAjzo6hRB6 fr7Q== X-Gm-Message-State: APjAAAUfC4h8cvWPVzQF77fJDm7Ifyjqtd0GctEqWdhmP3ymYBe7GYgp CNp5VV67gcXlhTpxzJt69b4= X-Google-Smtp-Source: APXvYqwWj6W4xNuOkRQhQaqGD4yIjteMZUOdV8oRYj6k6Zs0ZAvLj2NFCl9LTLQ8C4ldHdzp69d4LA== X-Received: by 2002:a17:906:251b:: with SMTP id i27mr6135129ejb.146.1553271168017; Fri, 22 Mar 2019 09:12:48 -0700 (PDT) Received: from archlinux-ryzen ([2a01:4f9:2a:1fae::2]) by smtp.gmail.com with ESMTPSA id u21sm1778965ejm.45.2019.03.22.09.12.46 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Fri, 22 Mar 2019 09:12:46 -0700 (PDT) Date: Fri, 22 Mar 2019 09:12:44 -0700 From: Nathan Chancellor To: Arnd Bergmann Cc: Jon Maloy , Ying Xue , "David S. Miller" , clang-built-linux@googlegroups.com, Nick Desaulniers , Tuong Lien , LUU Duc Canh , Tung Nguyen , GhantaKrishnamurthy MohanKrishna , netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tipc: avoid a clang -Wuninitialized warning Message-ID: <20190322161244.GG21978@archlinux-ryzen> References: <20190322141819.641588-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190322141819.641588-1-arnd@arndb.de> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Mar 22, 2019 at 03:18:13PM +0100, Arnd Bergmann wrote: > clang notices that we pass 'maddr' into the tipc_bearer_xmit() function > without having initialized it first: > > net/tipc/node.c:831:6: error: variable 'maddr' is used uninitialized whenever 'if' condition is false > [-Werror,-Wsometimes-uninitialized] > if (!tipc_link_is_establishing(l)) { > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > net/tipc/node.c:847:46: note: uninitialized use occurs here > tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr); > ^~~~~ > net/tipc/node.c:831:2: note: remove the 'if' if its condition is always true > if (!tipc_link_is_establishing(l)) { > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > net/tipc/node.c:821:31: note: initialize the variable 'maddr' to silence this warning > struct tipc_media_addr *maddr; > ^ > = NULL > > This is harmless because it won't use 'maddr' if the > queue is empty, but it's better to make that explicit > and not even call the function in that case. > > As clang is able to inline the check, it then notices that > the code is safe. > > Signed-off-by: Arnd Bergmann Thanks for looking into this and fixing it! Reviewed-by: Nathan Chancellor > --- > net/tipc/node.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/net/tipc/node.c b/net/tipc/node.c > index 2dc4919ab23c..ca4cafd00a38 100644 > --- a/net/tipc/node.c > +++ b/net/tipc/node.c > @@ -844,7 +844,8 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete) > tipc_node_write_unlock(n); > if (delete) > tipc_mon_remove_peer(n->net, n->addr, old_bearer_id); > - tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr); > + if (!skb_queue_empty(&xmitq)) > + tipc_bearer_xmit(n->net, bearer_id, &xmitq, maddr); > tipc_sk_rcv(n->net, &le->inputq); > } > > -- > 2.20.0 >