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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 CC846C43219 for ; Fri, 26 Apr 2019 07:39:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 96D0C20684 for ; Fri, 26 Apr 2019 07:39:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="lcL9mS3L" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726155AbfDZHjI (ORCPT ); Fri, 26 Apr 2019 03:39:08 -0400 Received: from mout.gmx.net ([212.227.17.22]:44451 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725912AbfDZHjI (ORCPT ); Fri, 26 Apr 2019 03:39:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1556264336; bh=eXVuQ4GxcSyfn1xn0uo5tTdWse+H/ZssVULo+dS1BoU=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date; b=lcL9mS3LSWTYbsmDr75NK0+owYv4AKZjIIcYOa8UGx5JB/gjP2Z9MyzVcJTieCEbT A02tQAMCB6AymIs1RLbNwZacgyUh9zDSZTzDbVJkrVVMFTxqrn7bPlFlcDtCvGt9Kg J/IhaJIhQLQSxUld3zwqIEWdrquTN9YeXN2tIf8o= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from localhost.localdomain ([218.18.229.179]) by mail.gmx.com (mrgmx102 [212.227.17.174]) with ESMTPSA (Nemesis) id 0LwXCt-1gjEo41SRD-018I5Y; Fri, 26 Apr 2019 09:38:56 +0200 From: Chengguang Xu To: gregkh@linuxfoundation.org Cc: dan.carpenter@oracle.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Chengguang Xu Subject: [RESEND PATCH] chardev: set variable ret to -EBUSY before checking minor range overlap Date: Fri, 26 Apr 2019 15:38:37 +0800 Message-Id: <20190426073837.23086-1-cgxu519@gmx.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:jnnTDKRqPbZvDx0A1eDgWqsaN67fPTgX38a3r2ZqdcyNAxNwdVI MZvaX+ciStiXcxrhZjAvRhm8j5wOD0RZl1Qi75+aQoY8IDD5kwGlF+mvEvZazW6Lqb8JG1K 0yG8G4I1bvxj5IqhR8BDtZfKuw5a/TnrDvUmoIYVgf5TdxXnhwRnzvbPuv8s9RRuZuHrauU 2sN2rLYhlpK0E8L1w/t2Q== X-UI-Out-Filterresults: notjunk:1;V03:K0:oNbZKfoyKYA=:Z8ApCNUhkpE/xtVgxngKFw 89Rlw4JFrb+XiV29Cbb5uPeu8llW8gbgJhHRuU6PV+jt5zE5UDyB3HPnxIRNGaU1qy0rSepGb Symvh75azF1L5hfukz7nSMJVCsS89ZDx9irMdhnbTQ/1hHnwf0UDrJHGT1YVftZUi9rEL8hnK Pou/R++bvpRDm1wFSzdXHKqQkv2ZawB+LcIal40xXYehI4lAuGS6xindXqqugT/I1nsUwIPqj EbJoZvNzoHUSTeTOcckZSncULF4t0PPJmqIwDrajN3HCUXTcPmT9trxk4wY7QpT2ZsZ5KMs8A 5jpnpiucAEyvqzUiFOAY8HQUWPOxiG2dKKTYccVB9se4KsR0+ireh6tOoh6G64G8zFIw/MQ/3 aDr11gV/dTuvhWr00Fjb1zGWhHoV5Amu42ACokIpeuUbW/CwGTHWLskxXy3tIvDZZKMEI/2pB HLvHtmdT6sjxZoqioGx+gmyc8qzxET3BSGHrsmvCf/0At3Nq9rlWnWWdzlFuy595FHFJ55fU/ MiaX0DY6g2j9WDn4yCHwSVel0+c7gt8TgFZhJpgD/kp/ASnEeQeHxuG+tqxn6m7906iBeewXH WBfsUDstrYa1nO1XqGNih8+C+UZ6Rfhb2znZ9WmwuLhkTm6Y1uBG2J+UyB0Ct4oCP435/pf28 KKSacRwGI4AOXuyWDrQj/zPAhMlDd7LpIJ6+S/N+za18/FhMMU1M6tiry4n4e9muFlNkQxo0H Txfmh+WDRYUaLcIUrMfoZc+M6zZqMFSQhosUoRG0ycVIOEbh1k6sS/AUlp8PTdHvddzjxUMnG OHwdaUwNxmBBl6tmLp/DV5KluW5PY4rFyyVTswWOnbH3QgA49emIxgQJ6HemGiZaDBydMV92K EoK+GbjAMTe5LDDVrzrbKnSJsJDmK2g1b4S8yDfzz+8/7iY0aMYKGi2TQNuLLn Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When allocating dynamic major, the minor range overlap check in __register_chrdev_region() will not fail, so actually there is no real case to passing non negative error code to caller. However, set variable ret to -EBUSY before chekcking minor range overlap will avoid false-positive warning from code analyzing tool(like Smatch) and also make the code more easy to understand. Suggested-by: Dan Carpenter Signed-off-by: Chengguang Xu =2D-- fs/char_dev.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/char_dev.c b/fs/char_dev.c index d18cad28c1c3..00dfe17871ac 100644 =2D-- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -98,7 +98,7 @@ __register_chrdev_region(unsigned int major, unsigned in= t baseminor, int minorct, const char *name) { struct char_device_struct *cd, *curr, *prev =3D NULL; - int ret =3D -EBUSY; + int ret; int i; if (major >=3D CHRDEV_MAJOR_MAX) { @@ -129,6 +129,7 @@ __register_chrdev_region(unsigned int major, unsigned = int baseminor, major =3D ret; } + ret =3D -EBUSY; i =3D major_to_index(major); for (curr =3D chrdevs[i]; curr; prev =3D curr, curr =3D curr->next) { if (curr->major < major) =2D- 2.20.1