diff -r a5c4ccc02285 -r 5d21d80777a6 master/ioctl.c
--- a/master/ioctl.c	Fri Sep 14 23:37:19 2018 +0200
+++ b/master/ioctl.c	Thu Sep 27 00:21:27 2018 +0200
@@ -1704,8 +1704,6 @@
     if (unlikely(!ctx->requested))
         return -EPERM;
 
-    io.process_data = NULL;
-
     /* Get the sum of the domains' process data sizes. */
 
     ctx->process_data_size = 0;
@@ -1735,18 +1733,6 @@
                     ctx->process_data + offset);
             offset += ecrt_domain_size(domain);
         }
-
-#ifdef EC_IOCTL_RTDM
-        /* RTDM uses a different approach for memory-mapping, which has to be
-         * initiated by the kernel.
-         */
-        ret = ec_rtdm_mmap(ctx, &io.process_data);
-        if (ret < 0) {
-            EC_MASTER_ERR(master, "Failed to map process data"
-                    " memory to user space (code %i).\n", ret);
-            return ret;
-        }
-#endif
     }
 
     io.process_data_size = ctx->process_data_size;