Index: adjkerntz.8
===================================================================
RCS file: /usr/home/ncvs/src/sbin/adjkerntz/adjkerntz.8,v
retrieving revision 1.29
diff -u -r1.29 adjkerntz.8
--- adjkerntz.8	13 Feb 2005 22:25:15 -0000	1.29
+++ adjkerntz.8	4 Jul 2006 21:45:42 -0000
@@ -148,6 +148,9 @@
 utility clears the kernel timezone structure and makes the kernel clock run
 in the UTC time zone.
 Super-user privileges are required for all operations.
+.Nm
+will exit cleanly before any adjustments have been made when executed in a
+jailed environment.
 .Sh ENVIRONMENT
 .Bl -tag -width Fl
 .It Ev TZ
Index: adjkerntz.c
===================================================================
RCS file: /usr/home/ncvs/src/sbin/adjkerntz/adjkerntz.c,v
retrieving revision 1.31
diff -u -r1.31 adjkerntz.c
--- adjkerntz.c	13 May 2006 11:58:58 -0000	1.31
+++ adjkerntz.c	4 Jul 2006 21:54:28 -0000
@@ -89,6 +89,7 @@
 	int initial_isdst = -1, final_isdst;
 	int need_restore = False, sleep_mode = False, looping,
 	    init = Unknown;
+	int jailed;
 	sigset_t mask, emask;
 
 	while ((ch = getopt(argc, argv, "ais")) != -1)
@@ -112,6 +113,13 @@
 	if (init == Unknown)
 		usage();
 
+	/* Exit early if we are in a jail(8) */
+	len = sizeof(jailed);
+	if (sysctlbyname("security.jail.jailed", &jailed, &len, NULL, 0) == 0) {
+		if (jailed != 0)
+			return 0;
+	}
+
 	if (access(_PATH_CLOCK, F_OK) != 0)
 		return 0;