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From: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
To: shuah@kernel.org, skhan@linuxfoundation.org,
	linux-kselftest@vger.kernel.org
Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
	tony.luck@intel.com, reinette.chatre@intel.com,
	babu.moger@amd.com, james.morse@arm.com,
	ravi.v.shankar@intel.com, fenghua.yu@intel.com, x86@kernel.org,
	linux-kernel@vger.kernel, dan.carpenter@oracle.com,
	dcb314@hotmail.com,
	Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Subject: [PATCH V2 12/19] selftests/resctrl: Enable gcc checks to detect buffer overflows
Date: Mon, 18 May 2020 15:08:32 -0700
Message-ID: <a53033f871303fae931f9f170ec225dd07b639f6.1589835155.git.sai.praneeth.prakhya@intel.com> (raw)
In-Reply-To: <cover.1589835155.git.sai.praneeth.prakhya@intel.com>

Feature Test Macros man page says the below about _FORTIFY_SOURCE

"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."

Enable this gcc check to catch buffer overflow bugs like the one in CMT
test.

Fixes: 78941183d1b1 ("selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest")
Reported-by: David Binderman <dcb314@hotmail.com>
Suggested-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
---
 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;
 
-- 
2.19.1


  parent reply index

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-18 22:08 [PATCH V2 00/19] Miscellaneous fixes for resctrl selftests Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 01/19] selftests/resctrl: Rename CQM test as CMT test Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 02/19] selftests/resctrl: Fix typo Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 03/19] selftests/resctrl: Fix typo in help text Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 04/19] selftests/resctrl: Declare global variables as extern Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 05/19] selftests/resctrl: Return if resctrl file system is not supported Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 06/19] selftests/resctrl: Check for resctrl mount point only if resctrl FS is supported Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 07/19] selftests/resctrl: Use resctrl/info for feature detection Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 08/19] selftests/resctrl: Ensure sibling CPU is not same as original CPU Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 09/19] selftests/resctrl: Fix missing options "-n" and "-p" Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 10/19] selftests/resctrl: Fix MBA/MBM results reporting format Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 11/19] selftests/resctrl: Abort running tests if not root user Sai Praneeth Prakhya
2020-05-18 22:08 ` Sai Praneeth Prakhya [this message]
2020-05-18 22:08 ` [PATCH V2 13/19] selftests/resctrl: Dynamically select buffer size for CAT test Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 14/19] selftests/resctrl: Skip the test if requested resctrl feature is not supported Sai Praneeth Prakhya
2020-05-20 23:46   ` Reinette Chatre
2020-05-21 17:12     ` Prakhya, Sai Praneeth
2020-05-18 22:08 ` [PATCH V2 15/19] selftests/resctrl: Change return type of umount_resctrlfs() to void Sai Praneeth Prakhya
2020-05-20 23:52   ` Reinette Chatre
2020-05-21 17:19     ` Prakhya, Sai Praneeth
2020-05-21 18:15       ` Reinette Chatre
2020-05-18 22:08 ` [PATCH V2 16/19] selftests/resctrl: Umount resctrl FS only if mounted Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 17/19] selftests/resctrl: Unmount resctrl FS after running all tests Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 18/19] selftests/resctrl: Fix incorrect parsing of iMC counters Sai Praneeth Prakhya
2020-05-18 22:08 ` [PATCH V2 19/19] selftests/resctrl: Fix checking for < 0 for unsigned values Sai Praneeth Prakhya
2020-05-21 16:12 ` [PATCH V2 00/19] Miscellaneous fixes for resctrl selftests Reinette Chatre
2020-05-21 17:28   ` Prakhya, Sai Praneeth

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