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;