selftests: sync: differentiate between sync unsupported and access errors

Sync test doesn't differentiate between sync unsupported and test run
by non-root user and treats both as unsupported cases.

Fix it to add handling for these two different scenarios.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.com>

1 files changed, 19 insertions, 4 deletions

diff --git a/tools/testing/selftests/sync/sync_test.c b/tools/testing/selftests/sync/sync_test.c
index 62fa666e501a..86ae45ad0347 100644
--- a/tools/testing/selftests/sync/sync_test.c
+++ b/tools/testing/selftests/sync/sync_test.c
@@ -31,6 +31,7 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <errno.h>
 
 #include "synctest.h"
 
@@ -56,18 +57,32 @@ static int run_test(int (*test)(void), char *name)
 static int sync_api_supported(void)
 {
         struct stat sbuf;
+        int ret;
+
+        ret = stat("/sys/kernel/debug/sync/sw_sync", &sbuf);
+        if (!ret)
+                return 0;
+
+        if (errno == ENOENT) {
+                printf("SKIP: Sync framework not supported by kernel\n");
+                exit(0);
+        }
+        if (errno == EACCES) {
+                printf("SKIP: Run Sync test as root.\n");
+                exit(0);
+        }
+
+        perror("stat");
+        exit(ret);
 
-        return 0 == stat("/sys/kernel/debug/sync/sw_sync", &sbuf);
 }
 
 int main(void)
 {
         int err = 0;
 
-        if (!sync_api_supported()) {
-                printf("SKIP: Sync framework not supported by kernel\n");
+        if (!sync_api_supported())
                 return 0;
-        }
 
         printf("[RUN]\tTesting sync framework\n");