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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 49B6AFA372A for ; Wed, 16 Oct 2019 14:58:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2D79C2168B for ; Wed, 16 Oct 2019 14:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389696AbfJPO6V (ORCPT ); Wed, 16 Oct 2019 10:58:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:36996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404400AbfJPO6R (ORCPT ); Wed, 16 Oct 2019 10:58:17 -0400 Received: from gandalf.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 62DE121A49; Wed, 16 Oct 2019 14:58:16 +0000 (UTC) Date: Wed, 16 Oct 2019 10:58:14 -0400 From: Steven Rostedt To: Miroslav Benes Cc: mingo@redhat.com, jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com, joe.lawrence@redhat.com, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, shuah@kernel.org, kamalesh@linux.vnet.ibm.com, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v3 0/3] ftrace: Introduce PERMANENT ftrace_ops flag Message-ID: <20191016105814.2061a106@gandalf.local.home> In-Reply-To: <20191016113316.13415-1-mbenes@suse.cz> References: <20191016113316.13415-1-mbenes@suse.cz> 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-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Oct 2019 13:33:12 +0200 Miroslav Benes wrote: > Livepatch uses ftrace for redirection to new patched functions. It means > that if ftrace is disabled, all live patched functions are disabled as > well. Toggling global 'ftrace_enabled' sysctl thus affect it directly. > It is not a problem per se, because only administrator can set sysctl > values, but it still may be surprising. > > Introduce PERMANENT ftrace_ops flag to amend this. If the > FTRACE_OPS_FL_PERMANENT is set on any ftrace ops, the tracing cannot be > disabled by disabling ftrace_enabled. Equally, a callback with the flag > set cannot be registered if ftrace_enabled is disabled. > > v2->v3: > - ftrace_enabled explicitly set to true > - selftest from Joe Lawrence (I just split it to two patches) > - typo fix > > v1->v2: > - different logic, proposed by Joe Lawrence > > Joe Lawrence (2): > selftests/livepatch: Make dynamic debug setup and restore generic > selftests/livepatch: Test interaction with ftrace_enabled > > Miroslav Benes (1): > ftrace: Introduce PERMANENT ftrace_ops flag > Would you like me to take all three patches through my tree? -- Steve