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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no 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 2C3A8C33C99 for ; Tue, 7 Jan 2020 06:29:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBACE2077B for ; Tue, 7 Jan 2020 06:29:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578378568; bh=GhOSuQQThHxmyW2srU1iYmKJZPiYeVV/Z+EWg2Jn4L8=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=N1Al9bNHyipCulH19zczRqUfLVOUVi3OcvQUcb3NHuNXJKKOa/6hfnA9kggiuaulW jB43BXvLJU6KiJA/iwFdOEoFyLk2w5m/4UI9DEb5HoL9tw23ipjj1C74jvEtE7kh0U kbXkeyfHO5YEXT7uCcCYSF7OZlKu6w59xh9Y3xw4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725914AbgAGG31 (ORCPT ); Tue, 7 Jan 2020 01:29:27 -0500 Received: from conssluserg-04.nifty.com ([210.131.2.83]:51037 "EHLO conssluserg-04.nifty.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725267AbgAGG31 (ORCPT ); Tue, 7 Jan 2020 01:29:27 -0500 Received: from mail-ua1-f46.google.com (mail-ua1-f46.google.com [209.85.222.46]) (authenticated) by conssluserg-04.nifty.com with ESMTP id 0076TA8c014378; Tue, 7 Jan 2020 15:29:10 +0900 DKIM-Filter: OpenDKIM Filter v2.10.3 conssluserg-04.nifty.com 0076TA8c014378 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nifty.com; s=dec2015msa; t=1578378551; bh=V4OXT4Fpyi9+NOlQeIWNoTFry/VXFE9skkoLr0JmobU=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=PUtkQKRh/fLDhr7OyI2jsy3dRzrVKjGRsJD26kFb8Yi5DYb3ZzVIj9aI89P3bCxO2 kcx+0mSsXbAq4C2G/aOvNTObJyA3sA7ZRSemwGljOlIhcw4yni6N1g0mkghKwLkTff PCvpPysq86Ay4TJqu/B05j3eWpmSKVpUV3flWj7fJbDYzYBRe9GDCcNj/9ZPgS6WVy mBpxYB8cwCaNXyhhFYC562rrdIJWQJ4ftIQllFGlOQDej1RK7yQoEXLAEkU4cuevXA FSB3dvO2xXez30a7IBaDz3GjYj6T2nLHidaWCSDoGt0mX8w317v0yQ6iasfpegGulk qbQdyYxrLIKew== X-Nifty-SrcIP: [209.85.222.46] Received: by mail-ua1-f46.google.com with SMTP id y23so18070021ual.2; Mon, 06 Jan 2020 22:29:10 -0800 (PST) X-Gm-Message-State: APjAAAX4OV0JdmY3G5sTMv5AWHnVrwQNu0DHhBg8VT2p58i/tMByElVg ROQnZfbu9nt9w1UAX2VzjdAUszkWFQxJNHz/+bk= X-Google-Smtp-Source: APXvYqypZNoHbzfj+w5gFDA3N15SQKWwFjdrHnOhN5aGCU+FKq8xDDltKeTcAoYEWk93oUB5yZ92m3AGy2jJt8IgSdk= X-Received: by 2002:ab0:2ea6:: with SMTP id y6mr41352359uay.25.1578378549666; Mon, 06 Jan 2020 22:29:09 -0800 (PST) MIME-Version: 1.0 References: <20200106045833.1725-1-masahiroy@kernel.org> <20200107051521.GF705@sol.localdomain> In-Reply-To: <20200107051521.GF705@sol.localdomain> From: Masahiro Yamada Date: Tue, 7 Jan 2020 15:28:33 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] treewide: remove redundent IS_ERR() before error code check To: Eric Biggers Cc: Andrew Morton , Julia Lawall , ACPI Devel Maling List , linux-arm-kernel , linux-clk , linux-crypto@vger.kernel.org, "open list:GPIO SUBSYSTEM" , linux-i2c@vger.kernel.org, Linux Kernel Mailing List , linux-mtd , Networking , ALSA Development Mailing List , DTML Content-Type: text/plain; charset="UTF-8" Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Tue, Jan 7, 2020 at 2:15 PM Eric Biggers wrote: > > On Mon, Jan 06, 2020 at 01:58:33PM +0900, Masahiro Yamada wrote: > > 'PTR_ERR(p) == -E*' is a stronger condition than IS_ERR(p). > > Hence, IS_ERR(p) is unneeded. > > > > The semantic patch that generates this commit is as follows: > > > > // > > @@ > > expression ptr; > > constant error_code; > > @@ > > -IS_ERR(ptr) && (PTR_ERR(ptr) == - error_code) > > +PTR_ERR(ptr) == - error_code > > // > > > > Signed-off-by: Masahiro Yamada > > Any reason for not doing instead: > > ptr == ERR_PTR(-error_code) > > ? Because there is no reason to change PTR_ERR(ptr) == -error_code to ptr == ERR_PTR(-error_code) if (PTR_ERR(ptr) == -error_code) style seems to be used more often. But, I think it is just a matter of preference after all. Both work equally fine. > To me it seems weird to use PTR_ERR() on non-error pointers. I even had to > double check that it returns a 'long' and not an 'int'. (If it returned an > 'int', it wouldn't work...) > > - Eric -- Best Regards Masahiro Yamada