From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753459AbeC1OFB (ORCPT ); Wed, 28 Mar 2018 10:05:01 -0400 Received: from mga11.intel.com ([192.55.52.93]:36624 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752572AbeC1OFA (ORCPT ); Wed, 28 Mar 2018 10:05:00 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,371,1517904000"; d="scan'208";a="29166235" Message-ID: <1522245880.520.1.camel@tzanussi-mobl.amr.corp.intel.com> Subject: Re: [PATCH] tracing: Uninitialized variable in create_tracing_map_fields() From: Tom Zanussi To: Dan Carpenter Cc: Steven Rostedt , Ingo Molnar , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Date: Wed, 28 Mar 2018 09:04:40 -0500 In-Reply-To: <20180328114815.GC29050@mwanda> References: <20180328114815.GC29050@mwanda> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Dan, On Wed, 2018-03-28 at 14:48 +0300, Dan Carpenter wrote: > Smatch complains that idx can be used uninitialized when we check if > (idx < 0). It has to be the first iteration through the loop and the > HIST_FIELD_FL_STACKTRACE bit has to be clear and the HIST_FIELD_FL_VAR > bit has to be set to reach the bug. > > Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers") > Signed-off-by: Dan Carpenter > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index 4f027642ceef..6aceee287d07 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -4411,7 +4411,7 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) > struct tracing_map *map = hist_data->map; > struct ftrace_event_field *field; > struct hist_field *hist_field; > - int i, idx; > + int i, idx = 0; > > for_each_hist_field(i, hist_data) { > hist_field = hist_data->fields[i]; Yes, this should definitely be initialized to 0, thanks for the patch! Acked-by: Tom Zanussi