From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756623Ab2LMSnx (ORCPT ); Thu, 13 Dec 2012 13:43:53 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37084 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756508Ab2LMSnw (ORCPT ); Thu, 13 Dec 2012 13:43:52 -0500 Message-ID: <50CA2194.40103@zytor.com> Date: Thu, 13 Dec 2012 10:42:28 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Borislav Petkov , Joe Perches , "Luck, Tony" , Jiri Kosina , Jeff Dike , Richard Weinberger , Thomas Gleixner , Ingo Molnar , "x86@kernel.org" , "linux-edac@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "user-mode-linux-devel@lists.sourceforge.net" , "user-mode-linux-user@lists.sourceforge.net" Subject: Re: [TRIVIAL PATCH 16/26] x86: Convert print_symbol to %pSR References: <054f8a88fe46ae0b4c2669d0e155d84c11b66115.1355335228.git.joe@perches.com> <20121212210959.GH8760@liondog.tnic> <1355347803.8538.16.camel@joe-AO722> <3908561D78D1C84285E8C5FCA982C28F1C969495@ORSMSX108.amr.corp.intel.com> <1355351039.27571.2.camel@joe-AO722> <20121212224550.GJ8760@liondog.tnic> <1355422990.13796.9.camel@joe-AO722> <20121213183659.GC31485@liondog.tnic> In-Reply-To: <20121213183659.GC31485@liondog.tnic> X-Enigmail-Version: 1.4.6 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/13/2012 10:37 AM, Borislav Petkov wrote: >> >> If appropriate, the code could be changed to >> >> (void *)(unsigned long)m->ip > > Can we explicitly cast it to what it is so that we can be explicit as to > what we're casting it? IOW: > > (void *)(__u64)m->ip; > > Does that even work on 32bit? > > Also, does the compiler bitch about this useless cast when building with > W=123? > Uh... no. The point is that (void *)(unsigned long) casts it to an integer of pointer size -- in userspace you would to (void *)(size_t) or (void *)(uintptr_t) -- so that the compiler knows "I meant to do that." -hpa