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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 C1216C47082 for ; Thu, 3 Jun 2021 11:10:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A332D60FDA for ; Thu, 3 Jun 2021 11:10:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229955AbhFCLLr (ORCPT ); Thu, 3 Jun 2021 07:11:47 -0400 Received: from mga07.intel.com ([134.134.136.100]:19667 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229721AbhFCLLq (ORCPT ); Thu, 3 Jun 2021 07:11:46 -0400 IronPort-SDR: p/duha5OTsNP2IHPFc1AMxiukk1DBRNN/5ujbsLG/lOGw4wqn/ffHj+7EEDF4fqVXHd8cpXB3R haibs1pb30jQ== X-IronPort-AV: E=McAfee;i="6200,9189,10003"; a="267883616" X-IronPort-AV: E=Sophos;i="5.83,244,1616482800"; d="scan'208";a="267883616" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jun 2021 04:10:01 -0700 IronPort-SDR: 40NLyzidrZVMzwXe2ce8BRDdTxNEnxAEH35sFi3l+yfgrveLgZpizD2GHJxMBSPUI9LyK6ybFv r8lrwFardnqQ== X-IronPort-AV: E=Sophos;i="5.83,244,1616482800"; d="scan'208";a="483433819" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jun 2021 04:09:59 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1lolEa-00GvRp-QS; Thu, 03 Jun 2021 14:09:56 +0300 Date: Thu, 3 Jun 2021 14:09:56 +0300 From: Andy Shevchenko To: "tiantao (H)" Cc: Tian Tao , gregkh@linuxfoundation.org, rafael@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, jonathan.cameron@huawei.com, song.bao.hua@hisilicon.com Subject: Re: [PATCH v3 3/3] drivers/base/node.c: use bin_attribute to avoid buff overflow Message-ID: References: <1622712162-7028-1-git-send-email-tiantao6@hisilicon.com> <1622712162-7028-4-git-send-email-tiantao6@hisilicon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 03, 2021 at 06:31:57PM +0800, tiantao (H) wrote: > 在 2021/6/3 17:53, Andy Shevchenko 写道: > > On Thu, Jun 03, 2021 at 05:22:42PM +0800, Tian Tao wrote: > > > Reading sys/devices/system/cpu/cpuX/nodeX/ returns cpumap and cpulist. > > > However, the size of this file is limited to PAGE_SIZE because of the > > > limitation for sysfs attribute. so we use bin_attribute instead of > > > attribute to avoid NR_CPUS too big to cause buff overflow. > > ... > > > > > } > > > -static DEVICE_ATTR_RO(cpumap); > > > -static inline ssize_t cpulist_show(struct device *dev, > > > - struct device_attribute *attr, > > > - char *buf) > > > +static BIN_ATTR_RO(cpumap, 0); > > So, you will have 2 blank lines in a row after this. Why one is not enough? > > Same question for other similar cases, if any. > >  I can delete the line 55. this is the only problem, are there any other > problems? I don't know. I'm not familiar with the area. -- With Best Regards, Andy Shevchenko