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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 706FDC433E1 for ; Mon, 24 Aug 2020 18:26:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 572EA20738 for ; Mon, 24 Aug 2020 18:26:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725962AbgHXS0j (ORCPT ); Mon, 24 Aug 2020 14:26:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:33564 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725946AbgHXS0j (ORCPT ); Mon, 24 Aug 2020 14:26:39 -0400 Received: from oasis.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6BDC4206BE; Mon, 24 Aug 2020 18:26:36 +0000 (UTC) Date: Mon, 24 Aug 2020 14:26:34 -0400 From: Steven Rostedt To: Andy Shevchenko Cc: David Laight , 'Nicolas Boichat' , "dianders@chromium.org" , "groeck@chromium.org" , Andrew Morton , Daniel Vetter , "Guilherme G. Piccoli" , Kars Mulder , Kees Cook , Masahiro Yamada , Michal Marek , Thomas Gleixner , Tiezhu Yang , Will Deacon , Yue Hu , "linux-kbuild@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v5] kernel/trace: Add DISALLOW_TRACE_PRINTK make option Message-ID: <20200824142634.235acc7d@oasis.local.home> In-Reply-To: <20200824134201.GM1891694@smile.fi.intel.com> References: <20200824105852.v5.1.I4feb11d34ce7a0dd5ee2c3327fb5a1a9a646be30@changeid> <3f84781f12424cbfa552981af42dfaf2@AcuMS.aculab.com> <20200824092828.4386bd25@oasis.local.home> <20200824134201.GM1891694@smile.fi.intel.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kbuild-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org On Mon, 24 Aug 2020 16:42:01 +0300 Andy Shevchenko wrote: > How making it make's option prevent some "smart" distros to achieve the same? > AFAIU any compile-time knob will allow to build a kernel w/o a feature and you > are against of such kernel builds in distros. Catch-22? Because it will fail the build if it finds a trace_printk() in the compiled code, but doesn't touch the config that is shipped, nor does it affect modules being built against this kernel. This patch series is for those that do not want a trace_printk() accidentally left behind in their own work and trigger that big warning and scare their users. But it still gives an option for developers to add a trace_printk. That is, the decision to have trace_printk in a particular output (vmlinux) is done at the compile time, and all it does is to make sure one isn't present at that moment. This series is not about keeping them out completely (test modules, etc), which a config option will. -- Steve