From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965299AbWJ2RCc (ORCPT ); Sun, 29 Oct 2006 12:02:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965303AbWJ2RCc (ORCPT ); Sun, 29 Oct 2006 12:02:32 -0500 Received: from nf-out-0910.google.com ([64.233.182.189]:8050 "EHLO nf-out-0910.google.com") by vger.kernel.org with ESMTP id S965299AbWJ2RCc (ORCPT ); Sun, 29 Oct 2006 12:02:32 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:date:from:to:cc:subject:message-id:mime-version:content-type:content-disposition:in-reply-to:user-agent; b=Fxz42NeShHvmWVVDjMmHlnxRgkK7+Q9rr7y5e8t+TtprrOmlEshH22TkJruk9CYtK07InXMHjTjx24wi5vCELQxWecw3dzqxipBQ7sKzKxJ+vx+8JSWhVqr1CbdZRj+hUarRdMlvYaoCdfgsZqE9Qek4PoSaMElB1B72wHgiLuk= Date: Sun, 29 Oct 2006 18:02:26 +0100 From: Luca Tettamanti To: "Robert P. J. Day" Cc: linux-kernel@vger.kernel.org Subject: Re: "signed" versus "__signed__" versus "__signed" in arch-specific "types.h" files Message-ID: <20061029170226.GA29903@dreamland.darkstar.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Robert P. J. Day ha scritto: > so the keyword alias "__signed__" is used early on in nearly every > types.h file but, if __KERNEL__ is defined, the file falls back to > just using "signed". (the use of "unsigned" is, of course, consistent > throughout.) When __KERNEL__ is not defined then that part of the header may be exposed to userspace[1]. Older compilers (or newer versions of gcc with -traditional used to compile old programs) don't recognize the keyword 'signed', hence the alternate keyword is used. Extreme backward compatibility I'd say ;) I doubt that today is possibile to compile anything with -traditional on a distro recent enough to use kernel 2.6. Luca [1] You'd better use the cleaned up version of the headers though. -- "It is more complicated than you think" -- The Eighth Networking Truth from RFC 1925