xsm: Error code consistency

Signed-off-by: Machon Gregory <mbgrego@tycho.ncsc.mil>

xen/include/xsm/xsm.h

@@ -427,7 +427,11 @@ static inline int xsm_remove_range (struct domain *d, char *name, unsigned long
 
 static inline long __do_xsm_op (XEN_GUEST_HANDLE(xsm_op_t) op)
 {
-    return xsm_call(__do_xsm_op(op));
+#ifdef XSM_ENABLE
+    return xsm_ops->__do_xsm_op(op);
+#else
+    return -ENOSYS;
+#endif
 }
 
 #ifdef XSM_ENABLE

xen/xsm/flask/flask_op.c

@@ -485,6 +485,9 @@ static int flask_security_sid(char *buf, uint32_t count)
     if ( length < 0 )
         goto out;
 
+    if ( len > count )
+        return -ERANGE; 
+
     memset(buf, 0, count);
     memcpy(buf, context, len);
     length = len;