kernel - Add sysref assertions

* Add more checks in the sysref code to detect use-after-free situations.

diff --git a/sys/sys/sysref2.h b/sys/sys/sysref2.h
index ce9bf08..1e765cf 100644 (file)
--- 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);
 }