From f34583c53380b1727c462556497d46bbd36df940 Mon Sep 17 00:00:00 2001
From: Pedro Martelletto <pedro@cvs.openbsd.org>
Date: Sat, 1 Nov 2008 21:35:36 +0000
Subject: Grab a reference to the trace vnode of the process when traversing
 the global process list and calling ktrsettracevnode() in ktrwrite(), so that
 we don't sleep in vrele(). Discussed with deraadt@, okay beck@, tedu@ and
 thib@.

---
 sys/kern/kern_ktrace.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/sys/kern/kern_ktrace.c b/sys/kern/kern_ktrace.c
index 91ec8956813..1c38f7f85fc 100644
--- a/sys/kern/kern_ktrace.c
+++ b/sys/kern/kern_ktrace.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: kern_ktrace.c,v 1.45 2008/10/31 17:17:02 deraadt Exp $	*/
+/*	$OpenBSD: kern_ktrace.c,v 1.46 2008/11/01 21:35:35 pedro Exp $	*/
 /*	$NetBSD: kern_ktrace.c,v 1.23 1996/02/09 18:59:36 christos Exp $	*/
 
 /*
@@ -466,11 +466,12 @@ ktrwrite(struct proc *p, struct ktr_header *kth)
 		aiov[1].iov_len = kth->ktr_len;
 		auio.uio_resid += kth->ktr_len;
 	}
-	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
+	vget(vp, LK_EXCLUSIVE | LK_RETRY, p);
 	error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, p->p_ucred);
-	VOP_UNLOCK(vp, 0, p);
-	if (!error)
-		return 0;
+	if (!error) {
+		vput(vp);
+		return (0);
+	}
 	/*
 	 * If error encountered, give up tracing on this vnode.
 	 */
@@ -483,7 +484,8 @@ ktrwrite(struct proc *p, struct ktr_header *kth)
 		}
 	}
 
-	return error;
+	vput(vp);
+	return (error);
 }
 
 /*
-- 
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