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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 04CB0C47404 for ; Mon, 7 Oct 2019 08:17:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D4E5020867 for ; Mon, 7 Oct 2019 08:17:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727302AbfJGIRS (ORCPT ); Mon, 7 Oct 2019 04:17:18 -0400 Received: from mx2.suse.de ([195.135.220.15]:56240 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727448AbfJGIRS (ORCPT ); Mon, 7 Oct 2019 04:17:18 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DC998AE46; Mon, 7 Oct 2019 08:17:16 +0000 (UTC) From: Miroslav Benes To: rostedt@goodmis.org, mingo@redhat.com, jpoimboe@redhat.com, jikos@kernel.org, pmladek@suse.com, joe.lawrence@redhat.com Cc: linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Miroslav Benes Subject: [PATCH 0/3] ftrace: Introduce PERMANENT ftrace_ops flag Date: Mon, 7 Oct 2019 10:17:11 +0200 Message-Id: <20191007081714.20259-1-mbenes@suse.cz> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: live-patching-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: live-patching@vger.kernel.org Livepatch uses ftrace for redirection to new patched functions. It is thus directly affected by ftrace sysctl knobs such as ftrace_enabled. Setting ftrace_enabled to 0 also disables all live patched functions. 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, the tracing of the function is not disabled. Such ftrace_ops can still be unregistered in a standard way. The patch set passes ftrace and livepatch kselftests. Miroslav Benes (3): ftrace: Make test_rec_ops_needs_regs() generic ftrace: Introduce PERMANENT ftrace_ops flag livepatch: Use FTRACE_OPS_FL_PERMANENT Documentation/trace/ftrace-uses.rst | 6 ++++ Documentation/trace/ftrace.rst | 2 ++ include/linux/ftrace.h | 8 +++-- kernel/livepatch/patch.c | 3 +- kernel/trace/ftrace.c | 47 ++++++++++++++++++++++++----- 5 files changed, 55 insertions(+), 11 deletions(-) -- 2.23.0