From patchwork Tue Oct 20 23:51:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fenghua Yu X-Patchwork-Id: 11848049 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AA57115E6 for ; Tue, 20 Oct 2020 23:52:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B1CD206DD for ; Tue, 20 Oct 2020 23:52:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2439379AbgJTXvh (ORCPT ); Tue, 20 Oct 2020 19:51:37 -0400 Received: from mga07.intel.com ([134.134.136.100]:11170 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439373AbgJTXvg (ORCPT ); Tue, 20 Oct 2020 19:51:36 -0400 IronPort-SDR: L3m76nZB5HpKSU54W36mhI+kaBgit+KQpftrv8M78NmypG4F6ZmjnWGqS0aHVZdbSpd/3dl3jo xhDz7dkGDL5g== X-IronPort-AV: E=McAfee;i="6000,8403,9780"; a="231486363" X-IronPort-AV: E=Sophos;i="5.77,399,1596524400"; d="scan'208";a="231486363" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Oct 2020 16:51:31 -0700 IronPort-SDR: Vxe1TAE6T12CTP0Vci295Q82Z8txNq3SEfDBI3qWyrg8o149QBh5beRD73orz/GcJIYclAKQmi SkRLVtp+Ix1Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,399,1596524400"; d="scan'208";a="320833850" Received: from otcwcpicx6.sc.intel.com ([172.25.55.29]) by orsmga006.jf.intel.com with ESMTP; 20 Oct 2020 16:51:31 -0700 From: Fenghua Yu To: "Shuah Khan" , "Reinette Chatre" , "Tony Luck" , "Babu Moger" , "James Morse" , "Borislav Petkov" , "Thomas Gleixner" , "Ravi V Shankar" Cc: "linux-kselftest" , "linux-kernel" , Fenghua Yu , David Binderman Subject: [PATCH v3 12/21] selftests/resctrl: Enable gcc checks to detect buffer overflows Date: Tue, 20 Oct 2020 23:51:17 +0000 Message-Id: <20201020235126.1871815-13-fenghua.yu@intel.com> X-Mailer: git-send-email 2.29.0 In-Reply-To: <20201020235126.1871815-1-fenghua.yu@intel.com> References: <20201020235126.1871815-1-fenghua.yu@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@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. Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest") 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 6ffb56c6a1e2..282ba7fcf17c 100644 --- a/tools/testing/selftests/resctrl/cmt_test.c +++ b/tools/testing/selftests/resctrl/cmt_test.c @@ -86,7 +86,7 @@ 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;