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 27CFCC47082 for ; Thu, 3 Jun 2021 09:53:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F148661057 for ; Thu, 3 Jun 2021 09:53:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229817AbhFCJzJ (ORCPT ); Thu, 3 Jun 2021 05:55:09 -0400 Received: from mga06.intel.com ([134.134.136.31]:44240 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229661AbhFCJzI (ORCPT ); Thu, 3 Jun 2021 05:55:08 -0400 IronPort-SDR: YSK4tgk1LlxGNK/cPWePiSadLqj7YB+5ingjal3DtmUpHnmcIkQcCVxaIS1vs93oQR5qBkKtYm 2z8pmfxkUh3Q== X-IronPort-AV: E=McAfee;i="6200,9189,10003"; a="265180960" X-IronPort-AV: E=Sophos;i="5.83,244,1616482800"; d="scan'208";a="265180960" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jun 2021 02:53:24 -0700 IronPort-SDR: uyEPPLgSCDKNELgIyYb6qvYzhUNE1Jz8SxVKSdd+x1yvjeQLF/YhYhlIvTPl2PwDFFOFfU3q7M IuCIWf6ZDSsw== X-IronPort-AV: E=Sophos;i="5.83,244,1616482800"; d="scan'208";a="550638310" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Jun 2021 02:53:22 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1lok2R-00GuWe-Oc; Thu, 03 Jun 2021 12:53:19 +0300 Date: Thu, 3 Jun 2021 12:53:19 +0300 From: Andy Shevchenko To: Tian Tao Cc: 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=us-ascii Content-Disposition: inline In-Reply-To: <1622712162-7028-4-git-send-email-tiantao6@hisilicon.com> 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 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. -- With Best Regards, Andy Shevchenko