From 6c49a8e295def754c6d902ca8563cce6571cfbf3 Mon Sep 17 00:00:00 2001
From: John Baldwin <jhb@FreeBSD.org>
Date: Fri, 4 May 2001 18:13:11 +0000
Subject: [PATCH] Fix a bug in the pfind() changes due to confusing the process
 returned by pfind() ('pp') with the process being detached from ptrace.

Reported by:	bde
---
 sys/kern/sys_process.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sys/kern/sys_process.c b/sys/kern/sys_process.c
index d08f342723e7..03640cf6e11d 100644
--- a/sys/kern/sys_process.c
+++ b/sys/kern/sys_process.c
@@ -381,7 +381,12 @@ ptrace(curp, uap)
 				struct proc *pp;
 
 				pp = pfind(p->p_oppid);
-				proc_reparent(p, pp ? pp : initproc);
+				if (pp != NULL)
+					PROC_UNLOCK(pp);
+				else
+					pp = initproc;
+				PROC_LOCK(p);
+				proc_reparent(p, pp);
 			} else
 				PROC_LOCK(p);
 			p->p_flag &= ~(P_TRACED | P_WAITED);