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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 027A2C71155 for ; Mon, 30 Nov 2020 20:22:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B70A22074A for ; Mon, 30 Nov 2020 20:22:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388398AbgK3UWC (ORCPT ); Mon, 30 Nov 2020 15:22:02 -0500 Received: from mga04.intel.com ([192.55.52.120]:60096 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387449AbgK3UWA (ORCPT ); Mon, 30 Nov 2020 15:22:00 -0500 IronPort-SDR: KF3JWiupJ1VHqTUNvOnWEY9zIBurFdvAN60/D33EfQLw2H/3nW4MH2jOYl4W980X4OdaWqqopi ZIEiiThT+HCg== X-IronPort-AV: E=McAfee;i="6000,8403,9821"; a="170140744" X-IronPort-AV: E=Sophos;i="5.78,382,1599548400"; d="scan'208";a="170140744" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Nov 2020 12:20:33 -0800 IronPort-SDR: 1MVlcWBJXCAxU009y0pqK/reLjsx1gn6xnICB3M4prAPmI7Y1rXs1ibbgvyVpNW6FSjCuvtfqy NjtQ+qokyb5A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,382,1599548400"; d="scan'208";a="480793794" Received: from otcwcpicx6.sc.intel.com ([172.25.55.29]) by orsmga004.jf.intel.com with ESMTP; 30 Nov 2020 12:20:32 -0800 From: Fenghua Yu To: "Shuah Khan" , "Tony Luck" , "Reinette Chatre" , "David Binderman" , "Babu Moger" , "James Morse" , "Ravi V Shankar" Cc: "linux-kernel" , Fenghua Yu Subject: [PATCH v4 11/17] selftests/resctrl: Enable gcc checks to detect buffer overflows Date: Mon, 30 Nov 2020 20:20:04 +0000 Message-Id: <20201130202010.178373-12-fenghua.yu@intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201130202010.178373-1-fenghua.yu@intel.com> References: <20201130202010.178373-1-fenghua.yu@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org David reported a buffer overflow error in the check_results() function of the cmt unit test and he suggested enabling _FORTIFY_SOURCE gcc compiler option to automatically detect any such errors. Feature Test Macros man page describes_FORTIFY_SOURCE as below "Defining this macro causes some lightweight checks to be performed to detect some buffer overflow errors when employing various string and memory manipulation functions (for example, memcpy, memset, stpcpy, strcpy, strncpy, strcat, strncat, sprintf, snprintf, vsprintf, vsnprintf, gets, and wide character variants thereof). For some functions, argument consistency is checked; for example, a check is made that open has been supplied with a mode argument when the specified flags include O_CREAT. Not all problems are detected, just some common cases. If _FORTIFY_SOURCE is set to 1, with compiler optimization level 1 (gcc -O1) and above, checks that shouldn't change the behavior of conforming programs are performed. With _FORTIFY_SOURCE set to 2, some more checking is added, but some conforming programs might fail. Some of the checks can be performed at compile time (via macros logic implemented in header files), and result in compiler warnings; other checks take place at run time, and result in a run-time error if the check fails. Use of this macro requires compiler support, available with gcc since version 4.0." Fix the buffer overflow error in the check_results() function of the cmt unit test and enable _FORTIFY_SOURCE gcc check to catch any future buffer overflow errors. Reported-by: David Binderman Suggested-by: David Binderman Signed-off-by: Fenghua Yu --- tools/testing/selftests/resctrl/Makefile | 2 +- tools/testing/selftests/resctrl/cmt_test.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile index d585cc1948cc..6bcee2ec91a9 100644 --- a/tools/testing/selftests/resctrl/Makefile +++ b/tools/testing/selftests/resctrl/Makefile @@ -1,5 +1,5 @@ CC = $(CROSS_COMPILE)gcc -CFLAGS = -g -Wall +CFLAGS = -g -Wall -O2 -D_FORTIFY_SOURCE=2 SRCS=$(wildcard *.c) OBJS=$(SRCS:.c=.o) diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c index 188b73b5a2cc..ac1a33d9ce12 100644 --- a/tools/testing/selftests/resctrl/cmt_test.c +++ b/tools/testing/selftests/resctrl/cmt_test.c @@ -81,7 +81,7 @@ static int check_results(struct resctrl_val_param *param, int no_of_bits) return errno; } - while (fgets(temp, 1024, fp)) { + while (fgets(temp, sizeof(temp), fp)) { char *token = strtok(temp, ":\t"); int fields = 0; -- 2.29.2