From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933939AbXGYQ5L (ORCPT ); Wed, 25 Jul 2007 12:57:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762675AbXGYQ45 (ORCPT ); Wed, 25 Jul 2007 12:56:57 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:53658 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758028AbXGYQ44 (ORCPT ); Wed, 25 Jul 2007 12:56:56 -0400 Date: Wed, 25 Jul 2007 09:56:12 -0700 (PDT) From: Linus Torvalds To: David Miller cc: jeremy@goop.org, hpa@zytor.com, kaos@ocs.com.au, xyzzy@speakeasy.org, viro@ftp.linux.org.uk, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: [PATCH][RFC] getting rid of stupid loop in BUG() In-Reply-To: <20070724.232914.56812376.davem@davemloft.net> Message-ID: References: <21803.1185331847@ocs10w.ocs.com.au> <46A6DB04.3000003@zytor.com> <46A6ECB7.7090208@goop.org> <20070724.232914.56812376.davem@davemloft.net> 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 On Tue, 24 Jul 2007, David Miller wrote: > > From: Jeremy Fitzhardinge > Date: Tue, 24 Jul 2007 23:24:55 -0700 > > > H. Peter Anvin wrote: > > > How far back was __builtin_trap() supported? > > > > I think its relatively recent, but it might be within our supported > > compiler window. > > I'm pretty sure it is. .. and I'm pretty sure it's immaterial. We don't just do the "ud2" instruction - we also do the file and line number information after it. Which means that __builtin_trap() is useless. So we might as well keep the loop, since both are two-byte instructions that tell gcc that it will never continue. Linus