Commit 1b0b3b99 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman

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: default avatarOliver Neukum <oneukum@suse.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 74e9f5fa
...@@ -21,6 +21,7 @@ ...@@ -21,6 +21,7 @@
void kref_init(struct kref *kref) void kref_init(struct kref *kref)
{ {
atomic_set(&kref->refcount,1); atomic_set(&kref->refcount,1);
smp_mb();
} }
/** /**
...@@ -31,6 +32,7 @@ void kref_get(struct kref *kref) ...@@ -31,6 +32,7 @@ void kref_get(struct kref *kref)
{ {
WARN_ON(!atomic_read(&kref->refcount)); WARN_ON(!atomic_read(&kref->refcount));
atomic_inc(&kref->refcount); atomic_inc(&kref->refcount);
smp_mb__after_atomic_inc();
} }
/** /**
......
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