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authorPatrick McHardy <kaber@trash.net>2010-04-09 16:42:15 +0200
committerPatrick McHardy <kaber@trash.net>2010-04-09 16:42:15 +0200
commited86308f6179d8fa6151c2d0f652aad0091548e2 (patch)
tree7a85671939266d2f80a03395f4c8af6f15f93948 /net/netfilter
parente9f13cab49f7f28b65a6f63201fca56480b2e059 (diff)
netfilter: remove invalid rcu_dereference() calls
The CONFIG_PROVE_RCU option discovered a few invalid uses of rcu_dereference() in netfilter. In all these cases, the code code intends to check whether a pointer is already assigned when performing registration or whether the assigned pointer matches when performing unregistration. The entire registration/ unregistration is protected by a mutex, so we don't need the rcu_dereference() calls. Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Tested-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter')
-rw-r--r--net/netfilter/nf_conntrack_ecache.c18
-rw-r--r--net/netfilter/nf_log.c8
2 files changed, 6 insertions, 20 deletions
diff --git a/net/netfilter/nf_conntrack_ecache.c b/net/netfilter/nf_conntrack_ecache.c
index d5a9bcd7d61b..849614af2322 100644
--- a/net/netfilter/nf_conntrack_ecache.c
+++ b/net/netfilter/nf_conntrack_ecache.c
@@ -81,11 +81,9 @@ 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);
- notify = rcu_dereference(nf_conntrack_event_cb);
- if (notify != NULL) {
+ if (nf_conntrack_event_cb != NULL) {
ret = -EBUSY;
goto out_unlock;
}
@@ -101,11 +99,8 @@ 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);
- notify = rcu_dereference(nf_conntrack_event_cb);
- BUG_ON(notify != new);
+ BUG_ON(nf_conntrack_event_cb != new);
rcu_assign_pointer(nf_conntrack_event_cb, NULL);
mutex_unlock(&nf_ct_ecache_mutex);
}
@@ -114,11 +109,9 @@ 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);
- notify = rcu_dereference(nf_expect_event_cb);
- if (notify != NULL) {
+ if (nf_expect_event_cb != NULL) {
ret = -EBUSY;
goto out_unlock;
}
@@ -134,11 +127,8 @@ 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);
- notify = rcu_dereference(nf_expect_event_cb);
- BUG_ON(notify != new);
+ BUG_ON(nf_expect_event_cb != 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 015725a5cd50..908f59935fbb 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -35,7 +35,6 @@ 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))
@@ -52,8 +51,7 @@ 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]);
- llog = rcu_dereference(nf_loggers[pf]);
- if (llog == NULL)
+ if (nf_loggers[pf] == NULL)
rcu_assign_pointer(nf_loggers[pf], logger);
}
@@ -65,13 +63,11 @@ 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++) {
- c_logger = rcu_dereference(nf_loggers[i]);
- if (c_logger == logger)
+ if (nf_loggers[i] == logger)
rcu_assign_pointer(nf_loggers[i], NULL);
list_del(&logger->list[i]);
}