From 1b0b3b9980e482ab7c603430462538334f69f14a Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Mon, 2 Apr 2007 14:47:59 +0200 Subject: [PATCH] kref: fix CPU ordering with respect to krefs some atomic operations are only atomic, not ordered. Thus a CPU is allowed to reorder memory references to an object to before the reference is obtained. This fixes it. Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- lib/kref.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/lib/kref.c b/lib/kref.c index 0d07cc31c818..a6dc3ec328e0 100644 --- a/lib/kref.c +++ b/lib/kref.c @@ -21,6 +21,7 @@ void kref_init(struct kref *kref) { atomic_set(&kref->refcount,1); + smp_mb(); } /** @@ -31,6 +32,7 @@ void kref_get(struct kref *kref) { WARN_ON(!atomic_read(&kref->refcount)); atomic_inc(&kref->refcount); + smp_mb__after_atomic_inc(); } /**