From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 466F5C3815B for ; Mon, 20 Apr 2020 17:25:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22EBE2078C for ; Mon, 20 Apr 2020 17:25:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726811AbgDTRZf (ORCPT ); Mon, 20 Apr 2020 13:25:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48860 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726729AbgDTRZe (ORCPT ); Mon, 20 Apr 2020 13:25:34 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47A3BC061A0C for ; Mon, 20 Apr 2020 10:25:34 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jQaAb-00032c-0O; Mon, 20 Apr 2020 19:25:21 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 32130101623; Mon, 20 Apr 2020 19:25:20 +0200 (CEST) From: Thomas Gleixner To: Christoph Hellwig Cc: LKML , x86@kernel.org, Kees Cook , Paolo Bonzini , Thomas Lendacky , Juergen Gross , Boris Ostrovsky Subject: Re: [patch 02/15] x86/cpu: Uninline CR4 accessors In-Reply-To: <20200420090102.GB24518@infradead.org> References: <20200419203137.214111265@linutronix.de> <20200419203335.856333226@linutronix.de> <20200420090102.GB24518@infradead.org> Date: Mon, 20 Apr 2020 19:25:20 +0200 Message-ID: <87v9luax33.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Christoph Hellwig writes: >> --- a/arch/x86/kernel/cpu/common.c >> +++ b/arch/x86/kernel/cpu/common.c >> @@ -387,7 +387,30 @@ void native_write_cr4(unsigned long val) >> bits_missing); >> } >> } >> -EXPORT_SYMBOL(native_write_cr4); >> +#if IS_MODULE(CONFIG_LKDTM) >> +EXPORT_SYMBOL_GPL(native_write_cr4); >> +#endif > > While this is better than what we had before we really need to have > a discussion on lkdtm - it needs a lot of crap that otherwise wouldn't > be exported, and I'm really worried about people enabling it and thus > adding exports even if they are conditional. Can we force the code > to be built in require a boot option for it to be activated? I can live with that :)