From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH] serial/8250: fix uninitialized warnings Date: Mon, 10 Nov 2008 15:58:08 -0800 Message-ID: <20081110155808.a4d94ee7.akpm@linux-foundation.org> References: <20081105022353.7CB0.KOSAKI.MOTOHIRO@jp.fujitsu.com> <20081104174142.360a964a@lxorguk.ukuu.org.uk> <20081110143039.6f21fdc3.akpm@linux-foundation.org> <20081110234843.0fba9f16@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:57531 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751340AbYKJX6x (ORCPT ); Mon, 10 Nov 2008 18:58:53 -0500 In-Reply-To: <20081110234843.0fba9f16@lxorguk.ukuu.org.uk> Sender: linux-serial-owner@vger.kernel.org List-Id: linux-serial@vger.kernel.org To: Alan Cox Cc: kosaki.motohiro@jp.fujitsu.com, linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, 10 Nov 2008 23:48:43 +0000 Alan Cox wrote: > > That's a regression in current gcc, surely? > > Oh and as a PS: Gcc is I believe right because if the loop is run zero > times then pos = NULL (ie n == NULL so the first BUG_ON fires) Whoa. That would be clever of it. On about half the architectures, BUG is not considered to be no-return. Dunno if that's a gcc shortcoming or if the architectures just haven't implemented it properly yet. This causes those architectures to generate quite a few warnings in generic code which don't appear on x86 (this would be one such case if your above theory is correct). This is fairly irritating of those architectures, as I keep on going in asking "what's up" and deciding "oh, that again".