net: sk_{detach|attach}_filter() rcu fixes
sk_attach_filter() and sk_detach_filter() are run with socket locked.
Use the appropriate rcu_dereference_protected() instead of blocking BH,
and rcu_dereference_bh().
There is no point adding BH prevention and memory barrier.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/filter.c b/net/core/filter.c
index 52b051f..7adf503 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -638,10 +638,9 @@
return err;
}
- rcu_read_lock_bh();
- old_fp = rcu_dereference_bh(sk->sk_filter);
+ old_fp = rcu_dereference_protected(sk->sk_filter,
+ sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp);
- rcu_read_unlock_bh();
if (old_fp)
sk_filter_delayed_uncharge(sk, old_fp);
@@ -654,14 +653,13 @@
int ret = -ENOENT;
struct sk_filter *filter;
- rcu_read_lock_bh();
- filter = rcu_dereference_bh(sk->sk_filter);
+ filter = rcu_dereference_protected(sk->sk_filter,
+ sock_owned_by_user(sk));
if (filter) {
rcu_assign_pointer(sk->sk_filter, NULL);
sk_filter_delayed_uncharge(sk, filter);
ret = 0;
}
- rcu_read_unlock_bh();
return ret;
}
EXPORT_SYMBOL_GPL(sk_detach_filter);