From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752275AbcEIH77 (ORCPT ); Mon, 9 May 2016 03:59:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55006 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751853AbcEIHSp (ORCPT ); Mon, 9 May 2016 03:18:45 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chunyu Hu , Steven Rostedt Subject: [PATCH 3.14 08/23] tracing: Dont display trigger file for events that cant be enabled Date: Mon, 9 May 2016 09:17:28 +0200 Message-Id: <20160509071647.155725486@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160509071646.726412064@linuxfoundation.org> References: <20160509071646.726412064@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chunyu Hu commit 854145e0a8e9a05f7366d240e2f99d9c1ca6d6dd upstream. Currently register functions for events will be called through the 'reg' field of event class directly without any check when seting up triggers. Triggers for events that don't support register through debug fs (events under events/ftrace are for trace-cmd to read event format, and most of them don't have a register function except events/ftrace/functionx) can't be enabled at all, and an oops will be hit when setting up trigger for those events, so just not creating them is an easy way to avoid the oops. Link: http://lkml.kernel.org/r/1462275274-3911-1-git-send-email-chuhu@redhat.com Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Chunyu Hu Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1546,8 +1546,13 @@ event_create_dir(struct dentry *parent, trace_create_file("filter", 0644, file->dir, file, &ftrace_event_filter_fops); - trace_create_file("trigger", 0644, file->dir, file, - &event_trigger_fops); + /* + * Only event directories that can be enabled should have + * triggers. + */ + if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) + trace_create_file("trigger", 0644, file->dir, file, + &event_trigger_fops); trace_create_file("format", 0444, file->dir, call, &ftrace_event_format_fops);