From 7f998e63df7d6579220d4244da685d3d9cd176d8 Mon Sep 17 00:00:00 2001
From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Thu, 12 Aug 2010 21:48:45 -0700
Subject: [PATCH] kernel - Add sysref assertions

* Add more checks in the sysref code to detect use-after-free situations.
---
 sys/sys/sysref2.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sys/sys/sysref2.h b/sys/sys/sysref2.h
index ce9bf0871a..1e765cf1b5 100644
--- a/sys/sys/sysref2.h
+++ b/sys/sys/sysref2.h
@@ -67,6 +67,7 @@ static __inline
 void
 sysref_get(struct sysref *sr)
 {
+	KKASSERT((sr->flags & SRF_PUTAWAY) == 0);
 	atomic_add_int(&sr->refcnt, 1);
 }
 
@@ -81,6 +82,7 @@ sysref_put(struct sysref *sr)
 {
 	int count = sr->refcnt;
 
+	KKASSERT((sr->flags & SRF_PUTAWAY) == 0);
 	if (count <= 1 || atomic_cmpset_int(&sr->refcnt, count, count - 1) == 0)
 		_sysref_put(sr);
 }
-- 
2.41.0