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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78470C04A68 for ; Thu, 28 Jul 2022 00:28:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232259AbiG1A2R (ORCPT ); Wed, 27 Jul 2022 20:28:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35526 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229505AbiG1A2O (ORCPT ); Wed, 27 Jul 2022 20:28:14 -0400 Received: from mail.nfschina.com (unknown [IPv6:2400:dd01:100f:2:72e2:84ff:fe10:5f45]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5E89D51436 for ; Wed, 27 Jul 2022 17:28:13 -0700 (PDT) Received: from localhost (unknown [127.0.0.1]) by mail.nfschina.com (Postfix) with ESMTP id 88D631E80D72; Thu, 28 Jul 2022 08:28:16 +0800 (CST) X-Virus-Scanned: amavisd-new at test.com Received: from mail.nfschina.com ([127.0.0.1]) by localhost (mail.nfschina.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id VSybt8IYnz-4; Thu, 28 Jul 2022 08:28:14 +0800 (CST) Received: from [172.30.38.102] (unknown [180.167.10.98]) (Authenticated sender: liqiong@nfschina.com) by mail.nfschina.com (Postfix) with ESMTPA id A6EED1E80CF5; Thu, 28 Jul 2022 08:28:13 +0800 (CST) Subject: Re: [PATCH] tracing: Do PTR_ERR() after IS_ERR() To: Steven Rostedt Cc: Ingo Molnar , linux-kernel@vger.kernel.org, yuzhe@nfschina.com, renyu@nfschina.com, jiaming@nfschina.com References: <20220727153519.6697-1-liqiong@nfschina.com> <20220727122847.6b00e29d@rorschach.local.home> From: liqiong Message-ID: Date: Thu, 28 Jul 2022 08:28:08 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20220727122847.6b00e29d@rorschach.local.home> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2022年07月28日 00:28, Steven Rostedt 写道: > On Wed, 27 Jul 2022 23:35:19 +0800 > Li Qiong wrote: > >> Check IS_ERR() firstly, then do PTR_ERR(). > Why? > > The code is fine as is. > > -- Steve > Hi, It's all right, assign PTR_ERR() to 'ret' anyway. But this assignment is valid only at the "IS_ERR()" path. Maybe it is better put "PTR_ERR()" at error path, keep the code clear. -- 李力琼 <13524287433> 上海市浦东新区海科路99号中科院上海高等研究院3号楼3楼