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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 04B22C31E5B for ; Mon, 17 Jun 2019 23:37:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CDDF4208C0 for ; Mon, 17 Jun 2019 23:37:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728722AbfFQXhC (ORCPT ); Mon, 17 Jun 2019 19:37:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:39184 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726808AbfFQXhC (ORCPT ); Mon, 17 Jun 2019 19:37:02 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D7454208C0; Mon, 17 Jun 2019 23:37:00 +0000 (UTC) Date: Mon, 17 Jun 2019 19:36:59 -0400 From: Steven Rostedt To: Divya Indi Cc: linux-kernel@vger.kernel.org, Srinivas Eeda , Aruna Ramakrishna Subject: Re: [PATCH 2/3] tracing: Adding additional NULL checks. Message-ID: <20190617193659.59b28700@gandalf.local.home> In-Reply-To: <1560357259-3497-3-git-send-email-divya.indi@oracle.com> References: <1560357259-3497-1-git-send-email-divya.indi@oracle.com> <1560357259-3497-2-git-send-email-divya.indi@oracle.com> <1560357259-3497-3-git-send-email-divya.indi@oracle.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 12 Jun 2019 09:34:18 -0700 Divya Indi wrote: > commit f45d1225adb0 ("tracing: Kernel access to Ftrace instances") > exported certain functions providing access to Ftrace instances from > other kernel components. I'm fine with the patch, the above statement is hard to understand. -- Steve > Adding some additional NULL checks to ensure safe usage by the users. > > Signed-off-by: Divya Indi > --- > kernel/trace/trace.c | 3 +++ > kernel/trace/trace_events.c | 2 ++ > 2 files changed, 5 insertions(+) > > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 1c80521..a60dc13 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -3205,6 +3205,9 @@ int trace_array_printk(struct trace_array *tr, > if (!(global_trace.trace_flags & TRACE_ITER_PRINTK)) > return 0; > > + if (!tr) > + return -EINVAL; > + > va_start(ap, fmt); > ret = trace_array_vprintk(tr, ip, fmt, ap); > va_end(ap); > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index b6b4618..445b059 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -800,6 +800,8 @@ int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set) > char *event = NULL, *sub = NULL, *match; > int ret; > > + if (!tr) > + return -ENODEV; > /* > * The buf format can be : > * *: means any event by that name.