From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753329AbdAZJf5 (ORCPT ); Thu, 26 Jan 2017 04:35:57 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:34616 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753295AbdAZJfv (ORCPT ); Thu, 26 Jan 2017 04:35:51 -0500 From: Taeung Song To: Arnaldo Carvalho de Melo Cc: linux-kernel@vger.kernel.org, Jiri Olsa , Namhyung Kim , Ingo Molnar , Peter Zijlstra , Wang Nan , Taeung Song Subject: [PATCH 3/3] perf ftrace: Handle NULL at write_tracing_file() Date: Thu, 26 Jan 2017 18:35:39 +0900 Message-Id: <1485423339-22780-3-git-send-email-treeze.taeung@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1485423339-22780-1-git-send-email-treeze.taeung@gmail.com> References: <1485423339-22780-1-git-send-email-treeze.taeung@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If a value for tracing file is NULL, segment fault error can occur using strlen(). Of course, currently the function don't be given NULL value. But write_tracing_file() can be generally used. So add the if statement. Cc: Jiri Olsa Cc: Namhyung Kim Signed-off-by: Taeung Song --- tools/perf/builtin-ftrace.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 8df5416..0754dee 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -54,8 +54,12 @@ static int write_tracing_file(const char *name, const char *val) { char *file; int fd, ret = -1; - ssize_t size = strlen(val); + ssize_t size; + if (val == NULL) + return -1; + + size = strlen(val); file = get_tracing_file(name); if (!file) { pr_debug("cannot get tracing file: %s\n", name); -- 2.7.4