Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935230Ab0KQSDd (ORCPT ); Wed, 17 Nov 2010 13:03:33 -0500 Received: from mx1.redhat.com ([209.132.183.28]:10851 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935136Ab0KQSDc (ORCPT ); Wed, 17 Nov 2010 13:03:32 -0500 Date: Wed, 17 Nov 2010 13:03:21 -0500 From: Dave Jones To: Linux Kernel Mailing List Cc: brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com Subject: Re: [S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking Message-ID: <20101117180320.GA13441@redhat.com> Mail-Followup-To: Dave Jones , Linux Kernel Mailing List , brueckner@linux.vnet.ibm.com, schwidefsky@de.ibm.com References: <201011162359.oAGNx3UN011130@hera.kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201011162359.oAGNx3UN011130@hera.kernel.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1409 Lines: 37 On Tue, Nov 16, 2010 at 11:59:03PM +0000, Linux Kernel wrote: > Gitweb: http://git.kernel.org/linus/ec6743bb06510c7b629603ce35713d6ae9273579 > Commit: ec6743bb06510c7b629603ce35713d6ae9273579 > Parent: ca768b663131ca644689fcadc9ca092dcc96a758 > Author: Hendrik Brueckner > AuthorDate: Wed Nov 10 10:05:55 2010 +0100 > Committer: Martin Schwidefsky > CommitDate: Wed Nov 10 10:05:54 2010 +0100 > > [S390] mm: add devmem_is_allowed() for STRICT_DEVMEM checking > > Provide the devmem_is_allowed() routine to restrict access to > kernel memory from userspace. > Set the CONFIG_STRICT_DEVMEM config option to switch on checking. > > Signed-off-by: Hendrik Brueckner > Signed-off-by: Martin Schwidefsky [snip add kconfig] ... > +static inline int devmem_is_allowed(unsigned long pfn) > +{ > + return 0; > +} So you add the config option that promises security, but then you always allow the access. This seems pointless ? Why bother having the option at all? Dave -- 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/