From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755501AbYDJA0U (ORCPT ); Wed, 9 Apr 2008 20:26:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752268AbYDJA0J (ORCPT ); Wed, 9 Apr 2008 20:26:09 -0400 Received: from terminus.zytor.com ([198.137.202.10]:58682 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750959AbYDJA0I (ORCPT ); Wed, 9 Apr 2008 20:26:08 -0400 Message-ID: <47FD5D42.5000603@zytor.com> Date: Wed, 09 Apr 2008 17:20:18 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.12 (X11/20080226) MIME-Version: 1.0 To: Steven Rostedt CC: LKML , Ingo Molnar , Peter Zijlstra , Linus Torvalds , akpm@osdl.org, Rusty Russell , Glauber de Oliveira Costa , Jan Beulich , Andi Kleen , Thomas Gleixner , pinskia@gcc.gnu.org Subject: Re: [PATCH] pop previous section in alternative.c References: In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Steven Rostedt wrote: > On Wed, 9 Apr 2008, Steven Rostedt wrote: > >> gcc expects all toplevel assembly to return to the original section type. >> The code in alteranative.c does not do this. This caused some strange bugs >> in sched-devel where code would end up in the .rodata section and when >> the kernel sets the NX bit on all .rodata, the kernel would crash when >> executing this code. >> >> This patch adds a .previous marker to return the code back to the >> original section. >> > > Oh, and this would not be complete without giving Andrew Pinski complete > credit for telling me it wasn't a gcc bug but a bug in the toplevel asm > code in the kernel. ;-) > In many ways it's kind of silly for this even to be in assembly, since all it is is a sequence of comma-separated byte values; I guess it was the easiest way to deal with it given the ".byte" prefix, but still... -hpa