diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
index 992bac8c352b..1fa4b86e1459 100644
--- a/tools/testing/selftests/resctrl/cache.c
+++ b/tools/testing/selftests/resctrl/cache.c
@@ -126,7 +126,7 @@ static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
 	if (!fp) {
 		ksft_perror("Failed to open results file");
 
-		return errno;
+		return -1;
 	}
 	if (fscanf(fp, "%lu", llc_occupancy) <= 0) {
 		ksft_perror("Could not get llc occupancy");
@@ -146,7 +146,7 @@ static int get_llc_occu_resctrl(unsigned long *llc_occupancy)
  * @llc_value:		perf miss value /
  *			llc occupancy value reported by resctrl FS
  *
- * Return:		0 on success. non-zero on failure.
+ * Return:		0 on success, < 0 on error.
  */
 static int print_results_cache(char *filename, int bm_pid,
 			       unsigned long llc_value)
@@ -161,7 +161,7 @@ static int print_results_cache(char *filename, int bm_pid,
 		if (!fp) {
 			ksft_perror("Cannot open results file");
 
-			return errno;
+			return -1;
 		}
 		fprintf(fp, "Pid: %d \t llc_value: %lu\n", bm_pid, llc_value);
 		fclose(fp);
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
index 9bb8ba93f433..fabb56ff68d1 100644
--- a/tools/testing/selftests/resctrl/cat_test.c
+++ b/tools/testing/selftests/resctrl/cat_test.c
@@ -53,7 +53,7 @@ static int check_results(struct resctrl_val_param *param, size_t span)
 	if (!fp) {
 		ksft_perror("Cannot open file");
 
-		return errno;
+		return -1;
 	}
 
 	while (fgets(temp, sizeof(temp), fp)) {
@@ -150,7 +150,7 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
 
 	if (pipe(pipefd)) {
 		ksft_perror("Unable to create pipe");
-		return errno;
+		return -1;
 	}
 
 	fflush(stdout);
diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
index 16fc0488e0a5..ffd302bd5c73 100644
--- a/tools/testing/selftests/resctrl/cmt_test.c
+++ b/tools/testing/selftests/resctrl/cmt_test.c
@@ -39,7 +39,7 @@ static int check_results(struct resctrl_val_param *param, size_t span, int no_of
 	if (!fp) {
 		ksft_perror("Error in opening file");
 
-		return errno;
+		return -1;
 	}
 
 	while (fgets(temp, sizeof(temp), fp)) {
diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
index 4988b93add6a..e907adf7cd25 100644
--- a/tools/testing/selftests/resctrl/mba_test.c
+++ b/tools/testing/selftests/resctrl/mba_test.c
@@ -111,7 +111,7 @@ static int check_results(void)
 	if (!fp) {
 		ksft_perror(output);
 
-		return errno;
+		return -1;
 	}
 
 	runs = 0;
diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
index 045cd7818c79..721b3ecbc158 100644
--- a/tools/testing/selftests/resctrl/mbm_test.c
+++ b/tools/testing/selftests/resctrl/mbm_test.c
@@ -61,7 +61,7 @@ static int check_results(size_t span)
 	if (!fp) {
 		ksft_perror(output);
 
-		return errno;
+		return -1;
 	}
 
 	runs = 0;
diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
index 231d2012de2b..7fd9f1010135 100644
--- a/tools/testing/selftests/resctrl/resctrl_val.c
+++ b/tools/testing/selftests/resctrl/resctrl_val.c
@@ -526,7 +526,7 @@ void signal_handler_unregister(void)
  * @bw_imc:		perf imc counter value
  * @bw_resc:		memory bandwidth value
  *
- * Return:		0 on success. non-zero on failure.
+ * Return:		0 on success, < 0 on error.
  */
 static int print_results_bw(char *filename,  int bm_pid, float bw_imc,
 			    unsigned long bw_resc)
@@ -542,14 +542,14 @@ static int print_results_bw(char *filename,  int bm_pid, float bw_imc,
 		if (!fp) {
 			ksft_perror("Cannot open results file");
 
-			return errno;
+			return -1;
 		}
 		if (fprintf(fp, "Pid: %d \t Mem_BW_iMC: %f \t Mem_BW_resc: %lu \t Difference: %lu\n",
 			    bm_pid, bw_imc, bw_resc, diff) <= 0) {
 			ksft_print_msg("Could not log results\n");
 			fclose(fp);
 
-			return errno;
+			return -1;
 		}
 		fclose(fp);
 	}
@@ -686,7 +686,7 @@ static void run_benchmark(int signum, siginfo_t *info, void *ucontext)
  * @benchmark_cmd:	benchmark command and its arguments
  * @param:		parameters passed to resctrl_val()
  *
- * Return:		0 on success. non-zero on failure.
+ * Return:		0 when the test was run, < 0 on error.
  */
 int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *param)
 {
@@ -814,7 +814,7 @@ int resctrl_val(const char * const *benchmark_cmd, struct resctrl_val_param *par
 	/* Signal child to start benchmark */
 	if (sigqueue(bm_pid, SIGUSR1, value) == -1) {
 		ksft_perror("sigqueue SIGUSR1 to child");
-		ret = errno;
+		ret = -1;
 		goto out;
 	}
 
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
index 77023d342a12..5fb595ed8843 100644
--- a/tools/testing/selftests/resctrl/resctrlfs.c
+++ b/tools/testing/selftests/resctrl/resctrlfs.c
@@ -88,7 +88,7 @@ int umount_resctrlfs(void)
 	if (umount(mountpoint)) {
 		ksft_perror("Unable to umount resctrl");
 
-		return errno;
+		return -1;
 	}
 
 	return 0;