11626 introduce /etc/versions/build
11627 clean up UUID code for ::status

@@ -18,11 +18,11 @@
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2017 Joyent, Inc.
+ * Copyright 2019 Joyent, Inc.
  */
 
 /*
  * Mdb kernel support module.  This module is loaded automatically when the
  * kvm target is initialized.  Any global functions declared here are exported

@@ -1807,6 +1807,22 @@
                 mdb_warn("failed to read 'nsec_per_tick'");
                 return (-1);
         }
 
         return ((ts/nsec) - lbi.lbi_debug_time);
+}
+
+void
+mdb_print_buildversion(void)
+{
+        GElf_Sym sym;
+
+        if (mdb_lookup_by_name("buildversion", &sym) != 0)
+                return;
+
+        char *str = mdb_zalloc(4096, UM_SLEEP | UM_GC);
+
+        if (mdb_readstr(str, 4096, sym.st_value) < 1)
+                return;
+
+        mdb_printf("build version: %s\n", str);
 }