Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965407AbXA3Fky (ORCPT ); Tue, 30 Jan 2007 00:40:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965410AbXA3Fky (ORCPT ); Tue, 30 Jan 2007 00:40:54 -0500 Received: from mailhub.sw.ru ([195.214.233.200]:18830 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965407AbXA3Fky (ORCPT ); Tue, 30 Jan 2007 00:40:54 -0500 To: schwidefsky@de.ibm.com Cc: Andrew Morton , Heiko Carstens , linux-kernel@vger.kernel.org, dmonakhov@openvz.org Subject: Re: + mm-search_binary_handler-mem-limit-fix.patch added to -mm tree References: <200701240909.l0O99IwK013495@shell0.pdx.osdl.net> <20070129113328.GA9941@osiris.boeblingen.de.ibm.com> <20070129135958.GB9941@osiris.boeblingen.de.ibm.com> <20070129093751.a1637a68.akpm@osdl.org> <1170094705.17738.11.camel@localhost> From: Dmitriy Monakhov Date: Tue, 30 Jan 2007 08:40:59 +0300 In-Reply-To: <1170094705.17738.11.camel@localhost> (Martin Schwidefsky's message of "Mon, 29 Jan 2007 19:18:25 +0100") Message-ID: <87veipxeac.fsf@sw.ru> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1608 Lines: 43 > > > The function changes mem limit to USER_DS before possible modprobe, but > > > never restored it again. Truly. The road to hell is paved with good intentions. Martin Schwidefsky writes: > On Mon, 2007-01-29 at 09:37 -0800, Andrew Morton wrote: >> hm, thanks for testing - I'll drop it. >> >> I don't really understand what's wrong with it though. Maybe it's settng >> USER_DS on kernel threads? > > For architectures with a split address space there has to be a call > set_fs(USER_DS) that switches from KERNEL_DS to USER_DS for the init > process. So far this has been done in search_binary_handler and > traditionally the kernel starts with KERNEL_DS to make the early > copy_from_user calls work. > So, what is wrong with always setting USER_DS? We are starting a user > space process after all. May be add some comment to prevent future attempts to make this place more "correct"? > > -- > blue skies, > Martin. > > Martin Schwidefsky > Linux for zSeries Development & Services > IBM Deutschland Entwicklung GmbH > > "Reality continues to ruin my life." - Calvin. > > > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/