Index: sys/kern/kern_fork.c
===================================================================
--- sys/kern/kern_fork.c	(revision 230617)
+++ sys/kern/kern_fork.c	(working copy)
@@ -59,6 +59,7 @@
 #include <sys/proc.h>
 #include <sys/procdesc.h>
 #include <sys/pioctl.h>
+#include <sys/ptrace.h>
 #include <sys/racct.h>
 #include <sys/resourcevar.h>
 #include <sys/sched.h>
@@ -702,7 +703,8 @@
 		 * for runaway child.
 		 */
 		td->td_dbgflags |= TDB_FORK;
-		td->td_dbg_forked = p2->p_pid;
+		td2->td_dbgflags |= TDB_FORK;
+		td->td_dbg_forked = td2->td_dbg_forked = p2->p_pid;
 		td2->td_dbgflags |= TDB_STOPATFORK;
 		_PHOLD(p2);
 		p2_held = 1;
@@ -731,6 +733,13 @@
 	knote_fork(&p1->p_klist, p2->p_pid);
 	SDT_PROBE(proc, kernel, , create, p2, p1, flags, 0, 0);
 
+	if (td->td_dbgflags & TDB_FORK) {
+		PTRACESTOP_SC(p1, td, S_PT_FORK);
+		PROC_LOCK(p1);
+		td->td_dbgflags &= ~TDB_FORK;
+		PROC_UNLOCK(p1);
+	}
+
 	/*
 	 * Wait until debugger is attached to child.
 	 */
@@ -1036,6 +1045,7 @@
 			proc_reparent(p, dbg);
 			sx_xunlock(&proctree_lock);
 			ptracestop(td, SIGSTOP);
+			td->td_dbgflags &= ~TDB_FORK;
 		} else {
 			/*
 			 * ... otherwise clear the request.
Index: sys/kern/sys_process.c
===================================================================
--- sys/kern/sys_process.c	(revision 230617)
+++ sys/kern/sys_process.c	(working copy)
@@ -868,10 +868,14 @@
 		break;
 
 	case PT_FOLLOW_FORK:
-		if (data)
+		if (data) {
 			p->p_flag |= P_FOLLOWFORK;
-		else
+			p->p_stops |= S_PT_FORK;
+		}
+		else {
 			p->p_flag &= ~P_FOLLOWFORK;
+			p->p_stops &= ~S_PT_FORK;
+		}
 		break;
 
 	case PT_STEP:
Index: sys/sys/ptrace.h
===================================================================
--- sys/sys/ptrace.h	(revision 230617)
+++ sys/sys/ptrace.h	(working copy)
@@ -142,6 +142,7 @@
  */
 #define	S_PT_SCE	0x000010000
 #define	S_PT_SCX	0x000020000
+#define	S_PT_FORK	0x000040000
 
 int	ptrace_set_pc(struct thread *_td, unsigned long _addr);
 int	ptrace_single_step(struct thread *_td);