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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 0E951C33CB1 for ; Thu, 16 Jan 2020 13:14:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3805206D5 for ; Thu, 16 Jan 2020 13:14:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="L2po0GTm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726871AbgAPNOC (ORCPT ); Thu, 16 Jan 2020 08:14:02 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:33521 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726278AbgAPNOC (ORCPT ); Thu, 16 Jan 2020 08:14:02 -0500 Received: by mail-pg1-f194.google.com with SMTP id 6so9889614pgk.0 for ; Thu, 16 Jan 2020 05:14:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=l8c+LvOlIaXBLMpBu+gnW139ZMvxJSLj7Fg/MJCqoms=; b=L2po0GTmDJ8kR90DFOh/ufd71rYkip97frpzmNT+4HWbSrpk9rgxTNGMqUCcRFtgwh r1Tafq1gj5s6qiworHQmH9T3KZDpehOyMpwoHysEWNaYxpdgBHZ0pXnhyvkkPlo0ULA8 Ymb/en+q9WIlBpDNAS3jCkNHGkL7e54559MhdO4Ws3tdc3EUOzeJubG6ebYtkNRqD0JU x3FdCcyLhtLmeIYSQQrb4mZgnQdL5Hds7U3ggWzI+7gFfcgcXy9YfzWoBM9qjIE5kJJg x+LiE4XXAXH0XHc7bv5vlEB6qbLnmhzTf1py/7zsiaUSXrvpR+x/XHAfp+VFbfpux8HN SL+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=l8c+LvOlIaXBLMpBu+gnW139ZMvxJSLj7Fg/MJCqoms=; b=FQGeJ8b7KmAqTSMRXczN9gn8RBrvLM3l9aLj4KUAPbHrqo8BsjWzDNRZJDz/TWYF4Z ZokyPIRdmH8ImKfpsq64KrU59qBIfoEJR5YdvrugI1Z5E3TrX/oE3Mht+R5lFR8nyArv 2dqfI7dc3HjUCaxjb5z0Oec5tXPgVvFAQgBHeQIPjtewpwANdOGeF48UUxGcipgSoU3+ SZm7N9XfLgE0K9WSSDJ6/2AG0f9tY3aIbR79FyEgQo2RQxNfYxFIcZnWSSF+p5AjfUIX UFMI/7om4U195kxGIx21qG6LCAnO/QE/ZaMzvJY2vFZ9t8yaFEWqz2q8fGNZTfXYLBMT CCVQ== X-Gm-Message-State: APjAAAVBq11lv9O93DKh/QRtAtRpS7rdG1OZef+LmFYJpBfNBVquKljX AcD+AG/Rfyh01uqRNwoW/9o= X-Google-Smtp-Source: APXvYqzAypaL2sxdWeKyCLNpEMehnVOUJkoJt1EeQHh6z5nBl19q2TL95svpni6xR6jP3Y9kMEgJow== X-Received: by 2002:a63:360a:: with SMTP id d10mr38192453pga.366.1579180441706; Thu, 16 Jan 2020 05:14:01 -0800 (PST) Received: from localhost.localdomain (FL1-122-135-105-104.tky.mesh.ad.jp. [122.135.105.104]) by smtp.gmail.com with ESMTPSA id g8sm25516092pfh.43.2020.01.16.05.13.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 16 Jan 2020 05:14:00 -0800 (PST) From: Masami Ichikawa To: rostedt@goodmis.org, mingo@redhat.com Cc: Masami Ichikawa , linux-kernel@vger.kernel.org Subject: [PATCH] tracing: Do not set trace clock if tracefs lockdown is in effect Date: Thu, 16 Jan 2020 22:12:36 +0900 Message-Id: <20200116131236.3866925-1-masami256@gmail.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200116094707.3846565-1-masami256@gmail.com> References: <20200116094707.3846565-1-masami256@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When trace_clock option is not set and unstable clcok detected, tracing_set_default_clock() sets trace_clock(ThinkPad A285 is one of case). In that case, if lockdown is in effect, null pointer dereference error happens in ring_buffer_set_clock(). Link: https://bugzilla.redhat.com/show_bug.cgi?id=1788488 Signed-off-by: Masami Ichikawa --- kernel/trace/trace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ddb7e7f5fe8d..5b6ee4aadc26 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9420,6 +9420,11 @@ __init static int tracing_set_default_clock(void) { /* sched_clock_stable() is determined in late_initcall */ if (!trace_boot_clock && !sched_clock_stable()) { + if (security_locked_down(LOCKDOWN_TRACEFS)) { + pr_warn("Can not set tracing clock due to lockdown\n"); + return -EPERM; + } + printk(KERN_WARNING "Unstable clock detected, switching default tracing clock to \"global\"\n" "If you want to keep using the local clock, then add:\n" -- 2.24.1