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 <eric.dumazet@gmail.com>

Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Patrick McHardy 2010-05-10 18:47:57 +02:00
parent 1e4b105712
commit b56f2d55c6
2 changed files with 26 additions and 6 deletions

View File

@ -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);
}

View File

@ -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]);
}