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

@@ -20,11 +20,11 @@
  */
 /*
  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2013 by Delphix. All rights reserved.
  *
- * Copyright 2018 Joyent, Inc.
+ * Copyright 2019 Joyent, Inc.
  */
 
 #include <kmdb/kmdb_kvm.h>
 #include <kmdb/kvm.h>
 #include <kmdb/kmdb_kdi.h>

@@ -47,10 +47,11 @@
 #include <dlfcn.h>
 #include <sys/isa_defs.h>
 #include <sys/kobj.h>
 #include <sys/kobj_impl.h>
 #include <sys/bitmap.h>
+#include <sys/uuid.h>
 #include <vm/as.h>
 
 static const char KMT_RTLD_NAME[] = "krtld";
 static const char KMT_MODULE[] = "mdb_ks";
 static const char KMT_CTFPARENT[] = "genunix";

@@ -550,11 +551,11 @@
 /*ARGSUSED*/
 static int
 kmt_status_dcmd(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
 {
         struct utsname uts;
-        char uuid[37];
+        char uuid[UUID_PRINTABLE_STRING_LENGTH];
         kreg_t tt;
 
         if (mdb_tgt_readsym(mdb.m_target, MDB_TGT_AS_VIRT, &uts, sizeof (uts),
             "unix", "utsname") != sizeof (uts)) {
                 warn("failed to read 'utsname' struct from kernel\n");

@@ -566,20 +567,18 @@
             (int)(sizeof (void *) * NBBY),
             (*uts.nodename == '\0' ? "(not set)" : uts.nodename));
         mdb_printf("operating system: %s %s (%s)\n",
             uts.release, uts.version, uts.machine);
 
-        if (mdb_tgt_readsym(mdb.m_target, MDB_TGT_AS_VIRT, uuid, sizeof (uuid),
-            "genunix", "dump_osimage_uuid") != sizeof (uuid)) {
-                warn("failed to read 'dump_osimage_uuid' string from kernel\n");
-                (void) strcpy(uuid, "(error)");
-        } else if (*uuid == '\0') {
-                (void) strcpy(uuid, "(not set)");
-        } else if (uuid[36] != '\0') {
-                (void) strcpy(uuid, "(invalid)");
+        mdb_print_buildversion();
+
+        if (mdb_readsym(uuid, sizeof (uuid),
+            "dump_osimage_uuid") == sizeof (uuid) &&
+            uuid[sizeof (uuid) - 1] == '\0') {
+                mdb_printf("image uuid: %s\n", uuid[0] != '\0' ?
+                    uuid : "(not set)");
         }
-        mdb_printf("image uuid: %s\n", uuid);
 
         mdb_printf("DTrace state: %s\n", (kmdb_kdi_dtrace_get_state() ==
             KDI_DTSTATE_DTRACE_ACTIVE ? "active (debugger breakpoints cannot "
             "be armed)" : "inactive"));