From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759484Ab2CGE6b (ORCPT ); Tue, 6 Mar 2012 23:58:31 -0500 Received: from mail-wi0-f174.google.com ([209.85.212.174]:43791 "EHLO mail-wi0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759431Ab2CGE63 (ORCPT ); Tue, 6 Mar 2012 23:58:29 -0500 Message-ID: <4F56EAE8.8060502@gmail.com> Date: Wed, 07 Mar 2012 12:58:16 +0800 From: Zhengwang Ruan User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.27) Gecko/20120216 Lightning/1.0b2 Thunderbird/3.1.19 MIME-Version: 1.0 To: =?UTF-8?B?QXJ2ZSBIasO4bm5ldsOlZw==?= CC: gregkh@linuxfoundation.org, chris+android@zenthought.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH 2/2 v2] Staging:android: Initialise buffer and buffer_size before used References: <1331087818-9942-1-git-send-email-ruan.zhengwang@gmail.com> <1331087818-9942-2-git-send-email-ruan.zhengwang@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -------- Original Message -------- From: Arve Hjønnevåg Sent: 2012年03月06日 星期二 20时01分58秒 To: Zhengwang Ruan Subject: Re: [PATCH 2/2 v2] Staging:android: Initialise buffer and buffer_size before used > On Tue, Mar 6, 2012 at 6:36 PM, Zhengwang Ruan wrote: >> GCC warns 'buffer' and 'buffer_size' are used with being uninitialized, and >> 'buffer' is used as returned value, and 'buffer_size' is initialized using >> uninitialized_var to clear warning. > Why do you clear the warning on buffer_size with uninitialized_var() > but not on buffer? struct binder_buffer *buffer; size_t buffer_size; struct rb_node *best_fit = NULL; I see 'best_fit' is initialized by being directly assigned a NULL pointer, I think it should be better to initialize pointer in this way. > Neither variable is used before being initialized. > I got the following compiling warning against buffer ans buffer_size: drivers/staging/android/binder.c:719:24: warning: ‘buffer’ may be used uninitialized in this function drivers/staging/android/binder.c:720:9: warning: ‘buffer_size’ may be used uninitialized in this function Thanks, -Zhengwang