Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760302AbZJMPfH (ORCPT ); Tue, 13 Oct 2009 11:35:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760297AbZJMPfG (ORCPT ); Tue, 13 Oct 2009 11:35:06 -0400 Received: from mail-fx0-f227.google.com ([209.85.220.227]:62982 "EHLO mail-fx0-f227.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760290AbZJMPfE (ORCPT ); Tue, 13 Oct 2009 11:35:04 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=MfzXjoClPAAFcV67hrb31afHxkTOIl82tKNA9Qe0HYjeTvUJStiqi8oJh/rcb1XhNT X9NlRov4uBCoMgJlYr+m6W0dLhsPdfFa7vMH80r1zr2AWhGRfLA29adDN7A7RXpFRPjA 5vrGk13+WuIxwXLsoqTJxQgQ3siiVARN6KRAQ= MIME-Version: 1.0 In-Reply-To: <20091013154943.1e1d3c3f@lxorguk.ukuu.org.uk> References: <817ecb6f0910121803p52a4049ep4a712545d28bba76@mail.gmail.com> <20091012213229.11898c12@infradead.org> <20091013060312.GA3215@elte.hu> <817ecb6f0910130435q56fcbf63r82fae9b94f3eb199@mail.gmail.com> <20091013070722.6e27b25e@infradead.org> <20091013141527.GA7053@elte.hu> <20091013072907.1daeba73@infradead.org> <20091013154943.1e1d3c3f@lxorguk.ukuu.org.uk> Date: Tue, 13 Oct 2009 11:34:26 -0400 Message-ID: <817ecb6f0910130834y1b039515q245d586e5e281fc6@mail.gmail.com> Subject: Re: [PATCH V5] x86: NX protection for kernel data From: Siarhei Liakh To: Alan Cox Cc: Arjan van de Ven , Ingo Molnar , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, James Morris , Andrew Morton , Andi Kleen , Rusty Russell , Thomas Gleixner , "H. Peter Anvin" , David Howells , Aristeu Rozanski Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1114 Lines: 23 >> I'd be surprised if anything ever did; this is the *kernel* mapping of >> the first megabyte, not some userspace mapping.... > > APM, BIOS32, EDD, PnPBIOS .. > > However except for APM (which isn't generally needed on NX capable > devices or found on them) none of them are usually on critical paths > because EDD is just grovelling around sort of stuff, and BIOS32 isn't > generally used by the kernel anyway so could probably cope with flipping > the permissions on the low 1 MB each call. Actually, I have posted a patch to fix RW+X problem with BIOS32 some time ago. See my submission to LKML (and subsequent discussion) on Jul 19 2009 "[PATCH] x86: Reducing footprint of BIOS32 service mappings". Nevertheless, that 1MB area is on my "to do" list, and I will be patching it sooner or later (assuming I get my patches tested well enough to get them accepted). -- 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/