From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753507AbcD0Qc5 (ORCPT ); Wed, 27 Apr 2016 12:32:57 -0400 Received: from mail.kernel.org ([198.145.29.136]:60510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753263AbcD0Qcy (ORCPT ); Wed, 27 Apr 2016 12:32:54 -0400 Message-Id: <20160427163250.999699171@goodmis.org> User-Agent: quilt/0.61-1 Date: Wed, 27 Apr 2016 12:32:30 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Tom Zanussi Subject: [for-next][PATCH 3/5] tracing: Add check for NULL event field when creating hist field References: <20160427163227.271103189@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0003-tracing-Add-check-for-NULL-event-field-when-creating.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tom Zanussi Smatch flagged create_hist_field() as possibly being able to dereference a NULL pointer, although the current code exits in all cases where the event field could be NULL, so it's not actually a problem. Still, to prevent future changes to the code from overlooking new cases, make the NULL pointer check explicit and warn once in that case. Link: http://lkml.kernel.org/r/cfbc003f534a3e441b4313272fd412310aba6336.1461610073.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index f98b6b3a2804..0c05b8a99806 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -371,6 +371,9 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, goto out; } + if (WARN_ON_ONCE(!field)) + goto out; + if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING; -- 2.8.0.rc3