selftests/resctrl: Close perf value read fd on errors

Perf event fd (fd_lm) is not closed when run_fill_buf() returns error.

Close fd_lm only in cat_val() to make it easier to track it is always
closed.

Fixes: 790bf585 ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/resctrl/cache.c

@@ -87,21 +87,19 @@ static int reset_enable_llc_perf(pid_t pid, int cpu_no)
 static int get_llc_perf(unsigned long *llc_perf_miss)
 {
 	__u64 total_misses;
+	int ret;
 
 	/* Stop counters after one span to get miss rate */
 
 	ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
 
-	if (read(fd_lm, &rf_cqm, sizeof(struct read_format)) == -1) {
+	ret = read(fd_lm, &rf_cqm, sizeof(struct read_format));
+	if (ret == -1) {
 		perror("Could not get llc misses through perf");
-
 		return -1;
 	}
 
 	total_misses = rf_cqm.values[0].value;
-
-	close(fd_lm);
-
 	*llc_perf_miss = total_misses;
 
 	return 0;
@@ -253,19 +251,25 @@ int cat_val(struct resctrl_val_param *param)
 					 memflush, operation, resctrl_val)) {
 				fprintf(stderr, "Error-running fill buffer\n");
 				ret = -1;
-				break;
+				goto pe_close;
 			}
 
 			sleep(1);
 			ret = measure_cache_vals(param, bm_pid);
 			if (ret)
-				break;
+				goto pe_close;
+
+			close(fd_lm);
 		} else {
 			break;
 		}
 	}
 
 	return ret;
+
+pe_close:
+	close(fd_lm);
+	return ret;
 }
 
 /*