Commit c83fa196 authored Apr 25, 2017 by Florian Westphal Committed by Pablo Neira Ayuso May 01, 2017

netfilter: nf_log: don't call synchronize_rcu in nf_log_unset

nf_log_unregister() (which is what gets called in the logger backends
module exit paths) does a (required, module is removed) synchronize_rcu().

But nf_log_unset() is only called from pernet exit handlers. It doesn't
free any memory so there appears to be no need to call synchronize_rcu.

v2: Liping Zhang points out that nf_log_unregister() needs to be called
after pernet unregister, else rmmod would become unsafe.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

parent 933bd83e

net/netfilter/nf_log.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -71,7 +71,6 @@ void nf_log_unset(struct net net, const struct nf_logger logger)
		RCU_INIT_POINTER(net->nf.nf_loggers[i], NULL);
		}
		mutex_unlock(&nf_log_mutex);
		synchronize_rcu();
		}
		EXPORT_SYMBOL(nf_log_unset);

+1 −1

Original line number	Diff line number	Diff line
		@@ -1140,10 +1140,10 @@ out:

		static void __exit nfnetlink_log_fini(void)
		{
		nf_log_unregister(&nfulnl_logger);
		nfnetlink_subsys_unregister(&nfulnl_subsys);
		netlink_unregister_notifier(&nfulnl_rtnl_notifier);
		unregister_pernet_subsys(&nfnl_log_net_ops);
		nf_log_unregister(&nfulnl_logger);
		}

		MODULE_DESCRIPTION("netfilter userspace logging");