Index: sys/kern/kern_exit.c
===================================================================
--- sys/kern/kern_exit.c
+++ sys/kern/kern_exit.c
@@ -355,6 +355,9 @@
 	 */
 	PROC_LOCK(p);
 	stopprofclock(p);
+	if ((p->p_flag & P_TRACED) != 0) {
+		p->p_flag2 |= P2_EXIT_TRACED;
+	}
 	p->p_flag &= ~(P_TRACED | P_PPWAIT | P_PPTRACE);
 	p->p_ptevents = 0;
 
@@ -996,11 +999,14 @@
 
 	switch (idtype) {
 	case P_ALL:
-		if (p->p_procdesc != NULL) {
-			PROC_UNLOCK(p);
-			return (0);
+		if (p->p_procdesc == NULL ||
+		   (p->p_pptr == td->td_proc &&
+		   ((p->p_flag & P_TRACED) != 0 ||
+		   (p->p_flag2 & P2_EXIT_TRACED) != 0))) {
+			break;
 		}
-		break;
+		PROC_UNLOCK(p);
+		return (0);
 	case P_PID:
 		if (p->p_pid != (pid_t)id) {
 			PROC_UNLOCK(p);
Index: sys/kern/sys_procdesc.c
===================================================================
--- sys/kern/sys_procdesc.c
+++ sys/kern/sys_procdesc.c
@@ -60,7 +60,6 @@
  *
  * Open questions:
  *
- * - How to handle ptrace(2)?
  * - Will we want to add a pidtoprocdesc(2) system call to allow process
  *   descriptors to be created for processes without pdfork(2)?
  */
Index: sys/sys/proc.h
===================================================================
--- sys/sys/proc.h
+++ sys/sys/proc.h
@@ -761,6 +761,7 @@
 #define	P2_ASLR_ENABLE	0x00000040	/* Force enable ASLR. */
 #define	P2_ASLR_DISABLE	0x00000080	/* Force disable ASLR. */
 #define	P2_ASLR_IGNSTART 0x00000100	/* Enable ASLR to consume sbrk area. */
+#define	P2_EXIT_TRACED	0x00000200	/* The process exited while it was traced. */
 
 /* Flags protected by proctree_lock, kept in p_treeflags. */
 #define	P_TREE_ORPHANED		0x00000001	/* Reparented, on orphan list */
Index: tests/sys/kern/ptrace_test.c
===================================================================
--- tests/sys/kern/ptrace_test.c
+++ tests/sys/kern/ptrace_test.c
@@ -3959,6 +3959,47 @@
 	ATF_REQUIRE(errno == ECHILD);
 }
 
+/*
+ * Ensure that traced processes created with pdfork(2) are visible to
+ * waitid(P_ALL).
+ */
+ATF_TC_WITHOUT_HEAD(ptrace__procdesc_wait_child);
+ATF_TC_BODY(ptrace__procdesc_wait_child, tc)
+{
+	pid_t child, wpid;
+	int pd, status;
+
+	child = pdfork(&pd, 0);
+	ATF_REQUIRE(child >= 0);
+
+	if (child == 0) {
+		trace_me();
+		(void)raise(SIGSTOP);
+		exit(0);
+	}
+
+	wpid = waitpid(child, &status, 0);
+	ATF_REQUIRE(wpid == child);
+	ATF_REQUIRE(WIFSTOPPED(status));
+	ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
+
+	ATF_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
+
+	wpid = wait(&status);
+	ATF_REQUIRE(wpid == child);
+	ATF_REQUIRE(WIFSTOPPED(status));
+	ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP);
+
+	ATF_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1);
+
+	wpid = wait(&status);
+	ATF_REQUIRE(wpid == child);
+	ATF_REQUIRE(WIFEXITED(status));
+	ATF_REQUIRE(WEXITSTATUS(status) == 0);
+
+	ATF_REQUIRE(close(pd) != -1);
+}
+
 ATF_TP_ADD_TCS(tp)
 {
 
@@ -4021,6 +4062,7 @@
 #endif
 	ATF_TP_ADD_TC(tp, ptrace__PT_LWPINFO_stale_siginfo);
 	ATF_TP_ADD_TC(tp, ptrace__proc_reparent);
+	ATF_TP_ADD_TC(tp, ptrace__procdesc_wait_child);
 
 	return (atf_no_error());
 }