[PATCH 5.11 185/342] selftests/resctrl: Fix compilation issues for global variables

From: Greg Kroah-Hartman
Date: Mon May 10 2021 - 07:41:00 EST


From: Fenghua Yu <fenghua.yu@xxxxxxxxx>

[ Upstream commit 8236c51d85a64643588505a6791e022cc8d84864 ]

Reinette reported following compilation issue on Fedora 32, gcc version
10.1.1

/usr/bin/ld: cqm_test.o:<src_dir>/cqm_test.c:22: multiple definition of
`cache_size'; cat_test.o:<src_dir>/cat_test.c:23: first defined here

The same issue is reported for long_mask, cbm_mask, count_of_bits etc
variables as well. Compiler isn't happy because these variables are
defined globally in two .c files namely cqm_test.c and cat_test.c and
the compiler during compilation finds that the variable is already
defined (multiple definition error).

Taking a closer look at the usage of these variables reveals that these
variables are used only locally in functions such as cqm_resctrl_val()
(defined in cqm_test.c) and cat_perf_miss_val() (defined in cat_test.c).
These variables are not shared between those functions. So, there is no
need for these variables to be global. Hence, fix this issue by making
them static variables.

Reported-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Tested-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/testing/selftests/resctrl/cat_test.c | 10 +++++-----
tools/testing/selftests/resctrl/cqm_test.c | 10 +++++-----
tools/testing/selftests/resctrl/resctrl.h | 2 +-
tools/testing/selftests/resctrl/resctrlfs.c | 10 +++++-----
4 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 5da43767b973..bdeeb5772592 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -17,10 +17,10 @@
#define MAX_DIFF_PERCENT 4
#define MAX_DIFF 1000000

-int count_of_bits;
-char cbm_mask[256];
-unsigned long long_mask;
-unsigned long cache_size;
+static int count_of_bits;
+static char cbm_mask[256];
+static unsigned long long_mask;
+static unsigned long cache_size;

/*
* Change schemata. Write schemata to specified
@@ -136,7 +136,7 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
return -1;

/* Get default cbm mask for L3/L2 cache */
- ret = get_cbm_mask(cache_type);
+ ret = get_cbm_mask(cache_type, cbm_mask);
if (ret)
return ret;

diff --git a/tools/testing/selftests/resctrl/cqm_test.c b/tools/testing/selftests/resctrl/cqm_test.c
index 5e7308ac63be..de33d1c0466e 100644
--- a/tools/testing/selftests/resctrl/cqm_test.c
+++ b/tools/testing/selftests/resctrl/cqm_test.c
@@ -16,10 +16,10 @@
#define MAX_DIFF 2000000
#define MAX_DIFF_PERCENT 15

-int count_of_bits;
-char cbm_mask[256];
-unsigned long long_mask;
-unsigned long cache_size;
+static int count_of_bits;
+static char cbm_mask[256];
+static unsigned long long_mask;
+static unsigned long cache_size;

static int cqm_setup(int num, ...)
{
@@ -125,7 +125,7 @@ int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd)
if (!validate_resctrl_feature_request("cqm"))
return -1;

- ret = get_cbm_mask("L3");
+ ret = get_cbm_mask("L3", cbm_mask);
if (ret)
return ret;

diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
index 39bf59c6b9c5..959c71e39bdc 100644
--- a/tools/testing/selftests/resctrl/resctrl.h
+++ b/tools/testing/selftests/resctrl/resctrl.h
@@ -92,7 +92,7 @@ void tests_cleanup(void);
void mbm_test_cleanup(void);
int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd);
void mba_test_cleanup(void);
-int get_cbm_mask(char *cache_type);
+int get_cbm_mask(char *cache_type, char *cbm_mask);
int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size);
void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
int cat_val(struct resctrl_val_param *param);
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 19c0ec4045a4..2a16100c9c3f 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -49,8 +49,6 @@ static int find_resctrl_mount(char *buffer)
return -ENOENT;
}

-char cbm_mask[256];
-
/*
* remount_resctrlfs - Remount resctrl FS at /sys/fs/resctrl
* @mum_resctrlfs: Should the resctrl FS be remounted?
@@ -205,16 +203,18 @@ int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size)
/*
* get_cbm_mask - Get cbm mask for given cache
* @cache_type: Cache level L2/L3
- *
- * Mask is stored in cbm_mask which is global variable.
+ * @cbm_mask: cbm_mask returned as a string
*
* Return: = 0 on success, < 0 on failure.
*/
-int get_cbm_mask(char *cache_type)
+int get_cbm_mask(char *cache_type, char *cbm_mask)
{
char cbm_mask_path[1024];
FILE *fp;

+ if (!cbm_mask)
+ return -1;
+
sprintf(cbm_mask_path, "%s/%s/cbm_mask", CBM_MASK_PATH, cache_type);

fp = fopen(cbm_mask_path, "r");
--
2.30.2