From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765066AbXHJChM (ORCPT ); Thu, 9 Aug 2007 22:37:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753103AbXHJCg4 (ORCPT ); Thu, 9 Aug 2007 22:36:56 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:46131 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751485AbXHJCgz convert rfc822-to-8bit (ORCPT ); Thu, 9 Aug 2007 22:36:55 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: YOSHIFUJI Hideaki / =?euc-jp?B?tcjGo7HRzMA=?= Cc: davem@davemloft.net, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, devel@openvz.org, adobriyan@sw.ru, netdev@vger.kernel.org Subject: Re: [PATCH 04/10] sysctl: Fix neighbour table sysctls. References: <20070809.184921.11594412.davem@davemloft.net> <20070810.111420.29442251.yoshfuji@linux-ipv6.org> <20070810.112915.63714468.yoshfuji@linux-ipv6.org> Date: Thu, 09 Aug 2007 20:35:55 -0600 In-Reply-To: <20070810.112915.63714468.yoshfuji@linux-ipv6.org> (YOSHIFUJI Hideaki's message of "Fri, 10 Aug 2007 11:29:15 +0900 (JST)") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=euc-jp Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org YOSHIFUJI Hideaki / µÈÆ£±ÑÌÀ writes: > In article (at Thu, 09 Aug 2007 > 20:23:16 -0600), ebiederm@xmission.com (Eric W. Biederman) says: > >> YOSHIFUJI Hideaki / µÈÆ£±ÑÌÀ writes: >> >> > Would you explain why it does not work properly >> > for those cases? >> >> Mostly no appropriate strategy routine was setup to >> report the data to the caller of sys_sysctl. > > I assume that default strategy have been existing for it, no?! > Maybe, I do miss something... I'd have to go through it case by case. But in general unless your proc_handler is proc_dointvec the default strategy routine which does a raw binary copy of your data out will generally do the wrong thing. So especially if your data is jiffies or otherwise needs processing you don't want to use the default strategy routine. Until relatively recently no one was really policing the sysctl interfaces and even now it isn't too serious. Eric