Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756692Ab3H3QgK (ORCPT ); Fri, 30 Aug 2013 12:36:10 -0400 Received: from terminus.zytor.com ([198.137.202.10]:52813 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754209Ab3H3QgI (ORCPT ); Fri, 30 Aug 2013 12:36:08 -0400 Message-ID: <5220C9C6.5020808@zytor.com> Date: Fri, 30 Aug 2013 09:35:18 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Steven Rostedt CC: Jan Kiszka , Fenghua Yu , Linux Kernel Mailing List , x86 , Ingo Molnar , Thomas Gleixner Subject: Re: x86-32: Early microcode loading stumbles over disabled DYNAMIC_FTRACE References: <5217908E.2040702@siemens.com> <5220BC1A.3030108@zytor.com> <20130830115142.1ee4c825@gandalf.local.home> In-Reply-To: <20130830115142.1ee4c825@gandalf.local.home> X-Enigmail-Version: 1.5.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 698 Lines: 20 On 08/30/2013 08:51 AM, Steven Rostedt wrote: > > It does when dynamic tracing is enabled. But this issue is with static > tracing, there's no code modification, thus all functions call > mcount/__fentry__ and we need to look at a variable to determine if we > should trace or not. > And of course global variables are a no-no without special handling in pre-paging mode. Sigh. You *could* bail out of the calling address is < PAGE_OFFSET. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/