Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932484AbWH1Jub (ORCPT ); Mon, 28 Aug 2006 05:50:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932477AbWH1Jub (ORCPT ); Mon, 28 Aug 2006 05:50:31 -0400 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:22719 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S932484AbWH1Jub (ORCPT ); Mon, 28 Aug 2006 05:50:31 -0400 Message-Id: <44F2D8A4.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0.1 Date: Mon, 28 Aug 2006 10:51:00 +0100 From: "Jan Beulich" To: "Jeremy Fitzhardinge" , "Andi Kleen" Cc: "Chuck Ebbert" <76306.1226@compuserve.com>, "H. J. Lu" , "Andrew Morton" , , "Zachary Amsden" Subject: Re: [PATCH RFC 3/6] Use %gs as the PDA base-segment in the kernel. References: <20060827084417.918992193@goop.org> <200608271757.18621.ak@suse.de> <44F1D464.5020304@goop.org> <200608272019.15067.ak@suse.de> In-Reply-To: <200608272019.15067.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 967 Lines: 26 >>> Andi Kleen 27.08.06 20:19 >>> >On Sunday 27 August 2006 19:20, Jeremy Fitzhardinge wrote: >> Andi Kleen wrote: >> >> +1: movw GS(%esp), %gs >> >> >> > >> > movl is recommended in 32bit mode >> > >> >> arch/i386/kernel/entry.S: Assembler messages: >> arch/i386/kernel/entry.S:334: Error: suffix or operands invalid for `mov' > >Looks like a gas bug to me. This was an intentional change (by H.J. if I recall right) as using movl with segment registers gives the incorrect impression that one gets a 32-bit memory access (especially for stores this is important, since there's really nothing stored to the upper 16 bits). One should always use suffix-less 'mov' for segment register accesses. Jan - 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/