selftests/resctrl: Make some strings passed to resctrlfs functions const

Control group, monitor group and resctrl_val are not mutated and
should not be mutated within resctrlfs.c functions.

Mark this by using const char * for the arguments.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/resctrl/resctrl.h

@@ -141,9 +141,10 @@ bool test_resource_feature_check(const struct resctrl_test *test);
 char *fgrep(FILE *inf, const char *str);
 int taskset_benchmark(pid_t bm_pid, int cpu_no, cpu_set_t *old_affinity);
 int taskset_restore(pid_t bm_pid, cpu_set_t *old_affinity);
-int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, const char *resource);
-int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
-			    char *resctrl_val);
+int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no,
+		   const char *resource);
+int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp,
+			    const char *mongrp, const char *resctrl_val);
 int perf_event_open(struct perf_event_attr *hw_event, pid_t pid, int cpu,
 		    int group_fd, unsigned long flags);
 unsigned char *alloc_buffer(size_t buf_size, int memflush);

tools/testing/selftests/resctrl/resctrlfs.c

@@ -534,8 +534,8 @@ static int write_pid_to_tasks(char *tasks, pid_t pid)
  *
  * Return: 0 on success, < 0 on error.
  */
-int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
-			    char *resctrl_val)
+int write_bm_pid_to_resctrl(pid_t bm_pid, const char *ctrlgrp,
+			    const char *mongrp, const char *resctrl_val)
 {
 	char controlgroup[128], monitorgroup[512], monitorgroup_p[256];
 	char tasks[1024];
@@ -593,7 +593,8 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp,
  *
  * Return: 0 on success, < 0 on error.
  */
-int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, const char *resource)
+int write_schemata(const char *ctrlgrp, char *schemata, int cpu_no,
+		   const char *resource)
 {
 	char controlgroup[1024], reason[128], schema[1024] = {};
 	int domain_id, fd, schema_len, ret = 0;