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=-9.0 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_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 9BE88C43219 for ; Thu, 2 May 2019 12:15:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6CBE420645 for ; Thu, 2 May 2019 12:15:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="XuabbuKV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726295AbfEBMPk (ORCPT ); Thu, 2 May 2019 08:15:40 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:42084 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726268AbfEBMPk (ORCPT ); Thu, 2 May 2019 08:15:40 -0400 Received: by mail-pg1-f194.google.com with SMTP id p6so967042pgh.9; Thu, 02 May 2019 05:15:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=auCY3PzhugcAdArS7AYx5TEJOOjQXZAWuV/mKevsN1Q=; b=XuabbuKVSY7a2TM5F6FvBFQn2davKNOV1y7Lr6scBDIEa+acuivbsLTj5HYd71Zzt6 sJXngEGEvlPSLXN6Gp2QAKTx9r4BhjQLOcyh7oyyT76eo0PW3t3uWf2K9M3wL2VrCqPb dzoE7YfVfatqZM4E1NjkZZtgSRXYjcVxPLUr0SUnS5VlrBhSYGhSl5oDmSqpzgeEOgD7 0IMQueDF6Kd1ijK2aE9FUd7xv+94J0F04o4H1UA6gtPVzfHORRGmZKo1MqN5D61FpTu2 W/lm74RDzcUfD7ZLUMg9YnHGvpsH6HOT1LNZhaAh6BWwyylOtktnXXxfV4+FzxkU6NPr GTig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=auCY3PzhugcAdArS7AYx5TEJOOjQXZAWuV/mKevsN1Q=; b=rfcdXzzZzGH6w+0z15YETqGAarJ+AIizvHLU79735ffnYhe+X0nN6OoH0xSBBilNNM CtJWMGxqxC57+TBCdFtj6SklQ8ymuFGRg+QrEJii8x4hIHMnh+ADObjtE6eBQ8nzFhxw VNCmSDx/O4f58/a7J4WOVKBWSphOM8god1ujHDebzhOiu2SENTab8SWuvVrm4ABDZWmC 6UiYt8fUKAq4d4cmd4yD+RrTjb+mhRCPGSOO0Amdxa8T8U5QtTHhq5uKSf+yLGqoBRFw s8lfxM9e1zKDtLFY8wNSSznvNydfmLpkwDay2Rxtcb8pbKXVopQZ5ZUh3TZEACCxHll2 vA7g== X-Gm-Message-State: APjAAAWgG0PmGwA2RQgujpW3/E+Nv33nGeIz9bIjwXn079y6gItmBQYb JBPw9k2MywNwRrmT7FJjqDc= X-Google-Smtp-Source: APXvYqyNDzr4VF4z/AVRLM0JxesMpf6pLO1/Hf/qL0RfemyI7luIkHnjwSRcCepUsyWRR+ut+H+Ryw== X-Received: by 2002:aa7:9116:: with SMTP id 22mr3801463pfh.165.1556799340062; Thu, 02 May 2019 05:15:40 -0700 (PDT) Received: from localhost.localdomain ([149.129.49.136]) by smtp.gmail.com with ESMTPSA id j9sm97547364pfc.43.2019.05.02.05.15.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 02 May 2019 05:15:39 -0700 (PDT) From: Chengguang Xu To: gregkh@linuxfoundation.org, dan.carpenter@oracle.com Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Chengguang Xu Subject: [PATCH v2] chardev: set variable ret to -EBUSY before checking minor range overlap Date: Thu, 2 May 2019 20:15:05 +0800 Message-Id: <1556799305-13288-1-git-send-email-cgxu519@gmail.com> X-Mailer: git-send-email 2.7.4 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@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 checking 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 --- v1->v2: - Rebase against the latest char-misc-next. - Modify signed-off mail address. 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 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -98,7 +98,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, int minorct, const char *name) { struct char_device_struct *cd, *curr, *prev = NULL; - int ret = -EBUSY; + int ret; int i; if (major >= CHRDEV_MAJOR_MAX) { @@ -129,6 +129,7 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor, major = ret; } + ret = -EBUSY; i = major_to_index(major); for (curr = chrdevs[i]; curr; prev = curr, curr = curr->next) { if (curr->major < major) -- 2.17.2