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=-6.8 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 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 525A3C10F13 for ; Mon, 8 Apr 2019 17:38:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 141882148E for ; Mon, 8 Apr 2019 17:38:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hQVD1vqA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728787AbfDHRiE (ORCPT ); Mon, 8 Apr 2019 13:38:04 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:43183 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726507AbfDHRiE (ORCPT ); Mon, 8 Apr 2019 13:38:04 -0400 Received: by mail-qk1-f193.google.com with SMTP id c20so8491130qkc.10 for ; Mon, 08 Apr 2019 10:38:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=7Bsy0HHiQI23+wIyYZlKH9CNuQ+Oq7f3gnuvXfO+9Zc=; b=hQVD1vqA0mW3ErlYiutqWj1yqPpk9QIiLU8tHlCmeKK/OloCqrcTw5vKPjjlpxoYBj 3Xy/3rI7TdcsQqOFh6MY+D67oP9VAI6lwtJ4OyAO7PBawIouKzQyuybYyxYOYikVMfLc 4628+MkM9hYLJ/FuPvb+KnTjW9TQZMe/Wz36Nww0GHZbsbJpdpPKKKCxrsRu+zTgXgbw IW7NuxJlJHZEMO1tZx6gWVhqG6FZ5KkwX4rmkH73VybDGy4HLseYWTKAez9w91LjTw96 YNinwurLvxqWnDwBe96M6jLF5BDYxSc+z4DbJYjBFzjvAhCE6O0dX/UtjHccs8wxMKmF ECrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=7Bsy0HHiQI23+wIyYZlKH9CNuQ+Oq7f3gnuvXfO+9Zc=; b=G6sO8hhwIiletQugXfZX64T9kszaK5VjpwjTAs7igJPgmadrmEZWtms7H6IIZWYGN5 CZTfHYNHhYLua5flBEFrf+4LmhtM6sxVXhNMF/ZJWHgHqxm2EP9PjL7VZXGIorspI4i/ kECrEG6HQEnI9nQhGiHmoQ9ACzqfADau1w8td2yDzWfxY+zBDdZ1qILoyVL6bSj3wDWX FGMGAtiCJAdvdk8eKZwefv3/pOOR0V9fCcp76/UVqGXnBK6VhLzoRi4FvCl+8wfflP7a H+3k68Klkr/yt4gAs642/mqC+3ltfiGTox1L+o0zwPtEf2yQ4GKzANMfSYorXEeEI7/u CfuA== X-Gm-Message-State: APjAAAUwUUSnpYvDqWlR/4cbjHQG3tef+mK2SqsrcE/MimUMymPfNI2+ 9JN79NJG7qLfJtRWtzjbfkdIlxH97XU= X-Google-Smtp-Source: APXvYqz+LqjRy1o/ppaWxQn/eTk86FXtlxBaiZ0V0810iap5MK7cWBQhEZXisW1Oo6fRSQbtYHHDmg== X-Received: by 2002:a37:434d:: with SMTP id q74mr24349502qka.177.1554745083157; Mon, 08 Apr 2019 10:38:03 -0700 (PDT) Received: from [172.17.120.85] ([179.184.205.250]) by smtp.gmail.com with ESMTPSA id n24sm20860887qtc.21.2019.04.08.10.37.59 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 08 Apr 2019 10:38:02 -0700 (PDT) Subject: Re: [PATCH] staging: gdm724x: Add parenthesis to Macro arguments To: Greg KH Cc: lkcamp@lists.libreplanetbr.org, realwakka@gmail.com, straube.linux@gmail.com, hle@owl.eu.com, rico.schrage@gmail.com, sophie.matter@web.de, Valentin.Vidic@carnet.hr, simon@nikanor.nu, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org References: <1554253445-28635-1-git-send-email-andredainez@gmail.com> <20190403042632.GA31130@kroah.com> From: Andre Message-ID: <0d8cd5e0-71f0-6748-08a6-84c3477c874d@gmail.com> Date: Mon, 8 Apr 2019 14:37:58 -0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190403042632.GA31130@kroah.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, thanks for replying. On 03/04/2019 01:26, Greg KH wrote: > On Tue, Apr 02, 2019 at 10:04:05PM -0300, Andre Dainez wrote: >> Fix checkpatch errors: >> >> CHECK: Macro argument 'len' may be better as '(len)' to avoid precedence issues >> CHECK: Macro argument 'nlh' may be better as '(nlh)' to avoid precedence issues >> >> Signed-off-by: Andre Dainez >> --- >> drivers/staging/gdm724x/netlink_k.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/staging/gdm724x/netlink_k.c b/drivers/staging/gdm724x/netlink_k.c >> index 92440c3..36d88f4 100644 >> --- a/drivers/staging/gdm724x/netlink_k.c >> +++ b/drivers/staging/gdm724x/netlink_k.c >> @@ -19,8 +19,8 @@ static DEFINE_MUTEX(netlink_mutex); >> #define ND_NLMSG_SPACE(len) (NLMSG_SPACE(len) + ND_IFINDEX_LEN) >> #define ND_NLMSG_DATA(nlh) ((void *)((char *)NLMSG_DATA(nlh) + \ >> ND_IFINDEX_LEN)) >> -#define ND_NLMSG_S_LEN(len) (len + ND_IFINDEX_LEN) >> -#define ND_NLMSG_R_LEN(nlh) (nlh->nlmsg_len - ND_IFINDEX_LEN) >> +#define ND_NLMSG_S_LEN(len) ((len) + ND_IFINDEX_LEN) > > This makes sense, but: > >> +#define ND_NLMSG_R_LEN(nlh) ((nlh)->nlmsg_len - ND_IFINDEX_LEN) > > That does not, correct? > Could you please clarify why this doesn't make sense? If, for some reason I calculate by hand the pointer address and call this macro like: ND_NLMSG_R_LEN(nlh + sizeof(*nlh)), then it would expand like nlh + sizeof(*nlh)->nlmsg_len - ND_IFINDEX_LEN which looks wrong in my pov, no? Please, let me know if I misunderstood anything. Thanks