diff --git a/components/lwp/lwp_syscall.c b/components/lwp/lwp_syscall.c
index b71f40f8d2177ce3cd89fd070d208641d0376acf..09c6556a234b79def62522ec008fd7a2edd18ff0 100644
--- a/components/lwp/lwp_syscall.c
+++ b/components/lwp/lwp_syscall.c
@@ -4080,11 +4080,21 @@ int sys_sched_getparam(pid_t pid, void *param)
 
 int sys_sched_get_priority_max(int policy)
 {
+    if(policy < 0)
+    {
+        rt_set_errno(EINVAL);
+        return -rt_get_errno();
+    }    
     return RT_THREAD_PRIORITY_MAX;
 }
 
 int sys_sched_get_priority_min(int policy)
 {
+    if(policy < 0)
+    {
+        rt_set_errno(EINVAL);
+        return -rt_get_errno();
+    }
     return 0;
 }
 
@@ -4116,7 +4126,10 @@ int sys_sched_getscheduler(int tid, int *policy, void *param)
 
 int sys_fsync(int fd)
 {
-    return fsync(fd);
+    int res = fsync(fd);
+    if (res < 0)
+        res = rt_get_errno();
+    return res;
 }
 
 const static void* func_table[] =