Index: head/sys/kern/kern_exec.c
===================================================================
--- head/sys/kern/kern_exec.c
+++ head/sys/kern/kern_exec.c
@@ -1051,6 +1051,8 @@
 	sigfastblock_clear(td);
 	umtx_exec(p);
 	itimers_exec(p);
+	if (sv->sv_onexec != NULL)
+		sv->sv_onexec(p, imgp);
 
 	EVENTHANDLER_DIRECT_INVOKE(process_exec, p, imgp);
 
Index: head/sys/kern/kern_exit.c
===================================================================
--- head/sys/kern/kern_exit.c
+++ head/sys/kern/kern_exit.c
@@ -72,6 +72,7 @@
 #include <sys/sdt.h>
 #include <sys/shm.h>
 #include <sys/sem.h>
+#include <sys/sysent.h>
 #include <sys/timers.h>
 #include <sys/umtx.h>
 #ifdef KTRACE
@@ -327,6 +328,9 @@
 
 	itimers_exit(p);
 
+	if (p->p_sysent->sv_onexit != NULL)
+		p->p_sysent->sv_onexit(p);
+
 	/*
 	 * Check if any loadable modules need anything done at process exit.
 	 * E.g. SYSV IPC stuff.
@@ -560,6 +564,9 @@
 	/* Save exit status. */
 	PROC_LOCK(p);
 	p->p_xthread = td;
+
+	if (p->p_sysent->sv_ontdexit != NULL)
+		p->p_sysent->sv_ontdexit(td);
 
 #ifdef KDTRACE_HOOKS
 	/*
Index: head/sys/kern/kern_kthread.c
===================================================================
--- head/sys/kern/kern_kthread.c
+++ head/sys/kern/kern_kthread.c
@@ -39,6 +39,7 @@
 #include <sys/resourcevar.h>
 #include <sys/rwlock.h>
 #include <sys/signalvar.h>
+#include <sys/sysent.h>
 #include <sys/sx.h>
 #include <sys/umtx.h>
 #include <sys/unistd.h>
@@ -355,6 +356,10 @@
 		PROC_UNLOCK(p);
 		kproc_exit(0);
 	}
+
+	if (p->p_sysent->sv_ontdexit != NULL)
+		p->p_sysent->sv_ontdexit(td);
+
 	tidhash_remove(td);
 	umtx_thread_exit(td);
 	tdsigcleanup(td);
Index: head/sys/kern/kern_thr.c
===================================================================
--- head/sys/kern/kern_thr.c
+++ head/sys/kern/kern_thr.c
@@ -353,6 +353,9 @@
 		return (0);
 	}
 
+	if (p->p_sysent->sv_ontdexit != NULL)
+		p->p_sysent->sv_ontdexit(td);
+
 	td->td_dbgflags |= TDB_EXIT;
 	if (p->p_ptevents & PTRACE_LWP) {
 		p->p_pendingexits++;
Index: head/sys/sys/sysent.h
===================================================================
--- head/sys/sys/sysent.h
+++ head/sys/sys/sysent.h
@@ -145,6 +145,9 @@
 	u_long		*sv_hwcap2;	/* Value passed in AT_HWCAP2. */
 	const char	*(*sv_machine_arch)(struct proc *);
 	vm_offset_t	sv_fxrng_gen_base;
+	void		(*sv_onexec)(struct proc *, struct image_params *);
+	void		(*sv_onexit)(struct proc *);
+	void		(*sv_ontdexit)(struct thread *td);
 };
 
 #define	SV_ILP32	0x000100	/* 32-bit executable. */