netfilter: nfnetlink: add rcu_dereference_protected() helpers (0eb5db7a) · Commits · 戴 / test

include/linux/netfilter/nfnetlink.h

+21 −0

Original line number	Diff line number	Diff line
		@@ -44,6 +44,27 @@ int nfnetlink_unicast(struct sk_buff skb, struct net net, u32 portid,

		void nfnl_lock(__u8 subsys_id);
		void nfnl_unlock(__u8 subsys_id);
		#ifdef CONFIG_PROVE_LOCKING
		int lockdep_nfnl_is_held(__u8 subsys_id);
		#else
		static inline int lockdep_nfnl_is_held(__u8 subsys_id)
		{
		return 1;
		}
		#endif /* CONFIG_PROVE_LOCKING */

		/*
		* nfnl_dereference - fetch RCU pointer when updates are prevented by subsys mutex
		*
		* @p: The pointer to read, prior to dereferencing
		* @ss: The nfnetlink subsystem ID
		*
		* Return the value of the specified RCU-protected pointer, but omit
		* both the smp_read_barrier_depends() and the ACCESS_ONCE(), because
		* caller holds the NFNL subsystem mutex.
		*/
		#define nfnl_dereference(p, ss) \
		rcu_dereference_protected(p, lockdep_nfnl_is_held(ss))

		#define MODULE_ALIAS_NFNL_SUBSYS(subsys) \
		MODULE_ALIAS("nfnetlink-subsys-" __stringify(subsys))

+8 −0

Original line number	Diff line number	Diff line
		@@ -61,6 +61,14 @@ void nfnl_unlock(__u8 subsys_id)
		}
		EXPORT_SYMBOL_GPL(nfnl_unlock);

		#ifdef CONFIG_PROVE_LOCKING
		int lockdep_nfnl_is_held(u8 subsys_id)
		{
		return lockdep_is_held(&table[subsys_id].mutex);
		}
		EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held);
		#endif

		int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n)
		{
		nfnl_lock(n->subsys_id);