From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755613AbYKNTDS (ORCPT ); Fri, 14 Nov 2008 14:03:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753236AbYKNTDH (ORCPT ); Fri, 14 Nov 2008 14:03:07 -0500 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:53914 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752042AbYKNTDG (ORCPT ); Fri, 14 Nov 2008 14:03:06 -0500 Date: Fri, 14 Nov 2008 19:01:49 +0000 From: Alan Cox To: David Howells Cc: dhowells@redhat.com, linux-serial@vger.kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] Fix an uninitialised variable warning in the 8250 driver Message-ID: <20081114190149.7f5c20f2@lxorguk.ukuu.org.uk> In-Reply-To: <26417.1226681468@redhat.com> References: <20081114163428.7b676742@lxorguk.ukuu.org.uk> <20081114162038.23016.20581.stgit@warthog.procyon.org.uk> <26417.1226681468@redhat.com> X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.12; x86_64-redhat-linux-gnu) Organization: Red Hat UK Cyf., Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SL4 1TE, Y Deyrnas Gyfunol. Cofrestrwyd yng Nghymru a Lloegr o'r rhif cofrestru 3798903 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 14 Nov 2008 16:51:08 +0000 David Howells wrote: > Alan Cox wrote: > > > Current versions of gcc that I've tested get this all correct just fine > > for x86 at least. > > gcc version 4.1.2 20070925 (Red Hat 4.1.2-33) Newer gcc (4.3 and above) gets it right. > x86_64 - which doesn't do that. It uses asm volatile and an infinite for-loop. Which it seems 4.3 knows about > Surely having BUG() retreat through a noreturn function may lose important > state, such as the function that issued the bug as the compiler is under no > requirement to save the return value, and the file/line info may not be > available. Its arch specific code so arch specific things can be done. Alan