From b56f2d55c6c22b0c5774b3b22e336fb6cc5f4094 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 10 May 2010 18:47:57 +0200 Subject: [PATCH] netfilter: use rcu_dereference_protected() Restore the rcu_dereference() calls in conntrack/expectation notifier and logger registration/unregistration, but use the _protected variant, which will be required by the upcoming __rcu annotations. Based on patch by Eric Dumazet Signed-off-by: Patrick McHardy --- net/netfilter/nf_conntrack_ecache.c | 22 ++++++++++++++++++---- net/netfilter/nf_log.c | 10 ++++++++-- 2 files changed, 26 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c index a94ac3ad02cb..cdcc7649476b 100644 --- a/net/netfilter/nf_conntrack_ecache.c +++ b/net/netfilter/nf_conntrack_ecache.c @@ -82,9 +82,12 @@ EXPORT_SYMBOL_GPL(nf_ct_deliver_cached_events); int nf_conntrack_register_notifier(struct nf_ct_event_notifier *new) { int ret = 0; + struct nf_ct_event_notifier *notify; mutex_lock(&nf_ct_ecache_mutex); - if (nf_conntrack_event_cb != NULL) { + notify = rcu_dereference_protected(nf_conntrack_event_cb, + lockdep_is_held(&nf_ct_ecache_mutex)); + if (notify != NULL) { ret = -EBUSY; goto out_unlock; } @@ -100,8 +103,12 @@ EXPORT_SYMBOL_GPL(nf_conntrack_register_notifier); void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *new) { + struct nf_ct_event_notifier *notify; + mutex_lock(&nf_ct_ecache_mutex); - BUG_ON(nf_conntrack_event_cb != new); + notify = rcu_dereference_protected(nf_conntrack_event_cb, + lockdep_is_held(&nf_ct_ecache_mutex)); + BUG_ON(notify != new); rcu_assign_pointer(nf_conntrack_event_cb, NULL); mutex_unlock(&nf_ct_ecache_mutex); } @@ -110,9 +117,12 @@ EXPORT_SYMBOL_GPL(nf_conntrack_unregister_notifier); int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *new) { int ret = 0; + struct nf_exp_event_notifier *notify; mutex_lock(&nf_ct_ecache_mutex); - if (nf_expect_event_cb != NULL) { + notify = rcu_dereference_protected(nf_expect_event_cb, + lockdep_is_held(&nf_ct_ecache_mutex)); + if (notify != NULL) { ret = -EBUSY; goto out_unlock; } @@ -128,8 +138,12 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_register_notifier); void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *new) { + struct nf_exp_event_notifier *notify; + mutex_lock(&nf_ct_ecache_mutex); - BUG_ON(nf_expect_event_cb != new); + notify = rcu_dereference_protected(nf_expect_event_cb, + lockdep_is_held(&nf_ct_ecache_mutex)); + BUG_ON(notify != new); rcu_assign_pointer(nf_expect_event_cb, NULL); mutex_unlock(&nf_ct_ecache_mutex); } diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c index 908f59935fbb..7df37fd786bc 100644 --- a/net/netfilter/nf_log.c +++ b/net/netfilter/nf_log.c @@ -35,6 +35,7 @@ static struct nf_logger *__find_logger(int pf, const char *str_logger) /* return EEXIST if the same logger is registred, 0 on success. */ int nf_log_register(u_int8_t pf, struct nf_logger *logger) { + const struct nf_logger *llog; int i; if (pf >= ARRAY_SIZE(nf_loggers)) @@ -51,7 +52,9 @@ int nf_log_register(u_int8_t pf, struct nf_logger *logger) } else { /* register at end of list to honor first register win */ list_add_tail(&logger->list[pf], &nf_loggers_l[pf]); - if (nf_loggers[pf] == NULL) + llog = rcu_dereference_protected(nf_loggers[pf], + lockdep_is_held(&nf_log_mutex)); + if (llog == NULL) rcu_assign_pointer(nf_loggers[pf], logger); } @@ -63,11 +66,14 @@ EXPORT_SYMBOL(nf_log_register); void nf_log_unregister(struct nf_logger *logger) { + const struct nf_logger *c_logger; int i; mutex_lock(&nf_log_mutex); for (i = 0; i < ARRAY_SIZE(nf_loggers); i++) { - if (nf_loggers[i] == logger) + c_logger = rcu_dereference_protected(nf_loggers[i], + lockdep_is_held(&nf_log_mutex)); + if (c_logger == logger) rcu_assign_pointer(nf_loggers[i], NULL); list_del(&logger->list[i]); } -- 2.20.1