v4.19.13 snapshot.
diff --git a/arch/um/kernel/umid.c b/arch/um/kernel/umid.c
new file mode 100644
index 0000000..10bf4ac
--- /dev/null
+++ b/arch/um/kernel/umid.c
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Licensed under the GPL
+ */
+
+#include <asm/errno.h>
+#include <init.h>
+#include <kern.h>
+#include <os.h>
+
+/* Changed by set_umid_arg */
+static int umid_inited = 0;
+
+static int __init set_umid_arg(char *name, int *add)
+{
+ int err;
+
+ if (umid_inited) {
+ os_warn("umid already set\n");
+ return 0;
+ }
+
+ *add = 0;
+ err = set_umid(name);
+ if (err == -EEXIST)
+ os_warn("umid '%s' already in use\n", name);
+ else if (!err)
+ umid_inited = 1;
+
+ return 0;
+}
+
+__uml_setup("umid=", set_umid_arg,
+"umid=<name>\n"
+" This is used to assign a unique identity to this UML machine and\n"
+" is used for naming the pid file and management console socket.\n\n"
+);
+