diff options
| author |   Patrick McHardy <kaber@trash.net> | 2014-02-18 18:06:48 +0000 |
|---|---|---|
| committer |   Pablo Neira Ayuso <pablo@netfilter.org> | 2014-02-25 11:29:21 +0100 |
| commit | 0eb5db7ad302a24fe6f0eb4bfd235357047a28db (patch) | |
| tree | 70ab0a2618925c66700ed7f7e47fe70793c550b4 /include | |
| parent | netfilter: ip_set: rename nfnl_dereference()/nfnl_set() (diff) | |
| download | linux-dev-0eb5db7ad302a24fe6f0eb4bfd235357047a28db.tar.xz linux-dev-0eb5db7ad302a24fe6f0eb4bfd235357047a28db.zip | |
netfilter: nfnetlink: add rcu_dereference_protected() helpers
Add a lockdep_nfnl_is_held() function and a nfnl_dereference() macro for
RCU dereferences protected by a NFNL subsystem mutex.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netfilter/nfnetlink.h | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/netfilter/nfnetlink.h b/include/linux/netfilter/nfnetlink.h index 28c74367e900..e955d4730625 100644 --- a/include/linux/netfilter/nfnetlink.h +++ b/include/linux/netfilter/nfnetlink.h @@ -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)) |