Index: head/share/man/man4/ddb.4
===================================================================
--- head/share/man/man4/ddb.4
+++ head/share/man/man4/ddb.4
@@ -60,7 +60,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 18, 2016
+.Dd June 6, 2016
 .Dt DDB 4
 .Os
 .Sh NAME
@@ -599,6 +599,13 @@
 header file for more details on the exact meaning of the structure fields.
 .\"
 .Pp
+.It Ic show Cm callout Ar addr
+Show information about the callout structure
+.Vt struct callout
+present at
+.Ar addr .
+.\"
+.Pp
 .It Ic show Cm cbstat
 Show brief information about the TTY subsystem.
 .\"
@@ -834,6 +841,10 @@
 complete object is printed.
 .\"
 .Pp
+.It Ic show Cm panic
+Print the panic message if set.
+.\"
+.Pp
 .It Ic show Cm page
 Show statistics on VM pages.
 .\"
Index: head/sys/kern/kern_shutdown.c
===================================================================
--- head/sys/kern/kern_shutdown.c
+++ head/sys/kern/kern_shutdown.c
@@ -929,3 +929,14 @@
 		strlcpy(kdh->panicstring, panicstr, sizeof(kdh->panicstring));
 	kdh->parity = kerneldump_parity(kdh);
 }
+
+#ifdef DDB
+DB_SHOW_COMMAND(panic, db_show_panic)
+{
+
+	if (panicstr == NULL)
+		db_printf("panicstr not set\n");
+	else
+		db_printf("panic: %s\n", panicstr);
+}
+#endif
Index: head/sys/kern/kern_timeout.c
===================================================================
--- head/sys/kern/kern_timeout.c
+++ head/sys/kern/kern_timeout.c
@@ -38,6 +38,7 @@
 __FBSDID("$FreeBSD$");
 
 #include "opt_callout_profiling.h"
+#include "opt_ddb.h"
 #if defined(__arm__)
 #include "opt_timer.h"
 #endif
@@ -60,6 +61,11 @@
 #include <sys/sysctl.h>
 #include <sys/smp.h>
 
+#ifdef DDB
+#include <ddb/ddb.h>
+#include <machine/_inttypes.h>
+#endif
+
 #ifdef SMP
 #include <machine/cpu.h>
 #endif
@@ -1615,3 +1621,34 @@
     CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
     0, 0, sysctl_kern_callout_stat, "I",
     "Dump immediate statistic snapshot of the scheduled callouts");
+
+#ifdef DDB
+static void
+_show_callout(struct callout *c)
+{
+
+	db_printf("callout %p\n", c);
+#define	C_DB_PRINTF(f, e)	db_printf("   %s = " f "\n", #e, c->e);
+	db_printf("   &c_links = %p\n", &(c->c_links));
+	C_DB_PRINTF("%" PRId64,	c_time);
+	C_DB_PRINTF("%" PRId64,	c_precision);
+	C_DB_PRINTF("%p",	c_arg);
+	C_DB_PRINTF("%p",	c_func);
+	C_DB_PRINTF("%p",	c_lock);
+	C_DB_PRINTF("%#x",	c_flags);
+	C_DB_PRINTF("%#x",	c_iflags);
+	C_DB_PRINTF("%d",	c_cpu);
+#undef	C_DB_PRINTF
+}
+
+DB_SHOW_COMMAND(callout, db_show_callout)
+{
+
+	if (!have_addr) {
+		db_printf("usage: show callout <struct callout *>\n");
+		return;
+	}
+
+	_show_callout((struct callout *)addr);
+}
+#endif /* DDB */