Le lundi 15 novembre 2010 Ã 17:53 +0100, Patrick McHardy a Ãcrit :
> On 15.11.2010 17:46, Eric Dumazet wrote:
> > @@ -49,11 +52,15 @@ EXPORT_SYMBOL(nf_register_queue_handler);
> > /* The caller must flush their queue before this */
> > int nf_unregister_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
> > {
> > + const struct nf_queue_handler *old;
> > +
> > if (pf >= ARRAY_SIZE(queue_handler))
> > return -EINVAL;
> >
> > mutex_lock(&queue_handler_mutex);
> > - if (queue_handler[pf] && queue_handler[pf] != qh) {
> > + old = rcu_dereference_protected(queue_handler[pf],
> > + lockdep_is_held(&queue_handler_mutex));
> > + if (old && old) {
>
> This doesn't look like it was intended :)
>
> if (old && old != qh)?
Thanks for the catch Patrick, here is an updated version.
[PATCH nf-next-2.6] netfilter: add __rcu annotations
Add some __rcu annotations and use helpers to reduce number of sparse
warnings (CONFIG_SPARSE_RCU_POINTER=y)
Signed-off-by: Eric Dumazet <eric.dumazet@xxxxxxxxx>
---
include/linux/netfilter.h | 6 ++---
include/net/netfilter/nf_conntrack_ecache.h | 4 +--
include/net/netfilter/nf_conntrack_l3proto.h | 2 -
net/netfilter/core.c | 4 +--
net/netfilter/nf_conntrack_expect.c | 6 ++---
net/netfilter/nf_conntrack_proto.c | 20 ++++++++++++-----
net/netfilter/nf_conntrack_standalone.c | 9 +++++--
net/netfilter/nf_log.c | 6 +++--
net/netfilter/nf_queue.c | 18 +++++++++++----
net/netfilter/nfnetlink_log.c | 6 ++---
10 files changed, 53 insertions(+), 28 deletions(-)
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 89341c3..928a35e 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -265,7 +265,7 @@ struct nf_afinfo {
int route_key_size;
};
-extern const struct nf_afinfo *nf_afinfo[NFPROTO_NUMPROTO];
+extern const struct nf_afinfo __rcu *nf_afinfo[NFPROTO_NUMPROTO];
static inline const struct nf_afinfo *nf_get_afinfo(unsigned short family)
{
return rcu_dereference(nf_afinfo[family]);
@@ -355,9 +355,9 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
#endif /*CONFIG_NETFILTER*/
#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
-extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
+extern void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu;
extern void nf_ct_attach(struct sk_buff *, struct sk_buff *);
-extern void (*nf_ct_destroy)(struct nf_conntrack *);
+extern void (*nf_ct_destroy)(struct nf_conntrack *) __rcu;
#else
static inline void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb) {}
#endif
diff --git a/include/net/netfilter/nf_conntrack_ecache.h b/include/net/netfilter/nf_conntrack_ecache.h
index f596b60..8fdb04b 100644
--- a/include/net/netfilter/nf_conntrack_ecache.h
+++ b/include/net/netfilter/nf_conntrack_ecache.h
@@ -67,7 +67,7 @@ struct nf_ct_event_notifier {
int (*fcn)(unsigned int events, struct nf_ct_event *item);
};
-extern struct nf_ct_event_notifier *nf_conntrack_event_cb;
+extern struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb;
extern int nf_conntrack_register_notifier(struct nf_ct_event_notifier *nb);
extern void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *nb);
@@ -167,7 +167,7 @@ struct nf_exp_event_notifier {
int (*fcn)(unsigned int events, struct nf_exp_event *item);
};
-extern struct nf_exp_event_notifier *nf_expect_event_cb;
+extern struct nf_exp_event_notifier __rcu *nf_expect_event_cb;
extern int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *nb);
extern void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *nb);
diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h
index a754761..e8010f4 100644
--- a/include/net/netfilter/nf_conntrack_l3proto.h
+++ b/include/net/netfilter/nf_conntrack_l3proto.h
@@ -73,7 +73,7 @@ struct nf_conntrack_l3proto {
struct module *me;
};
-extern struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX];
+extern struct nf_conntrack_l3proto __rcu *nf_ct_l3protos[AF_MAX];
/* Protocol registration. */
extern int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto);
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index 85dabb8..5faec4f 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -212,7 +212,7 @@ EXPORT_SYMBOL(skb_make_writable);
/* This does not belong here, but locally generated errors need it if connection
tracking in use: without this, connection may not be in hash table, and hence
manufactured ICMP or RST packets will not be associated with it. */
-void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *);
+void (*ip_ct_attach)(struct sk_buff *, struct sk_buff *) __rcu __read_mostly;
EXPORT_SYMBOL(ip_ct_attach);
void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb)
@@ -229,7 +229,7 @@ void nf_ct_attach(struct sk_buff *new, struct sk_buff *skb)
}
EXPORT_SYMBOL(nf_ct_attach);
-void (*nf_ct_destroy)(struct nf_conntrack *);
+void (*nf_ct_destroy)(struct nf_conntrack *) __rcu __read_mostly;
EXPORT_SYMBOL(nf_ct_destroy);
void nf_conntrack_destroy(struct nf_conntrack *nfct)
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 46e8966..cab196c 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -482,7 +482,7 @@ static struct hlist_node *ct_expect_get_first(struct seq_file *seq)
struct hlist_node *n;
for (st->bucket = 0; st->bucket < nf_ct_expect_hsize; st->bucket++) {
- n = rcu_dereference(net->ct.expect_hash[st->bucket].first);
+ n = rcu_dereference(hlist_first_rcu(&net->ct.expect_hash[st->bucket]));
if (n)
return n;
}
@@ -495,11 +495,11 @@ static struct hlist_node *ct_expect_get_next(struct seq_file *seq,
struct net *net = seq_file_net(seq);
struct ct_expect_iter_state *st = seq->private;
- head = rcu_dereference(head->next);
+ head = rcu_dereference(hlist_next_rcu(head));
while (head == NULL) {
if (++st->bucket >= nf_ct_expect_hsize)
return NULL;
- head = rcu_dereference(net->ct.expect_hash[st->bucket].first);
+ head = rcu_dereference(hlist_first_rcu(&net->ct.expect_hash[st->bucket]));
}
return head;
}
diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c
index dc7bb74..03b56a0 100644
--- a/net/netfilter/nf_conntrack_proto.c
+++ b/net/netfilter/nf_conntrack_proto.c
@@ -166,6 +166,7 @@ static void nf_ct_l3proto_unregister_sysctl(struct nf_conntrack_l3proto *l3proto
int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
{
int ret = 0;
+ struct nf_conntrack_l3proto *old;
if (proto->l3proto >= AF_MAX)
return -EBUSY;
@@ -174,7 +175,9 @@ int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto)
return -EINVAL;
mutex_lock(&nf_ct_proto_mutex);
- if (nf_ct_l3protos[proto->l3proto] != &nf_conntrack_l3proto_generic) {
+ old = rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
+ lockdep_is_held(&nf_ct_proto_mutex));
+ if (old != &nf_conntrack_l3proto_generic) {
ret = -EBUSY;
goto out_unlock;
}
@@ -201,7 +204,9 @@ void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto)
BUG_ON(proto->l3proto >= AF_MAX);
mutex_lock(&nf_ct_proto_mutex);
- BUG_ON(nf_ct_l3protos[proto->l3proto] != proto);
+ BUG_ON(rcu_dereference_protected(nf_ct_l3protos[proto->l3proto],
+ lockdep_is_held(&nf_ct_proto_mutex)
+ ) != proto);
rcu_assign_pointer(nf_ct_l3protos[proto->l3proto],
&nf_conntrack_l3proto_generic);
nf_ct_l3proto_unregister_sysctl(proto);
@@ -299,8 +304,10 @@ int nf_conntrack_l4proto_register(struct nf_conntrack_l4proto *l4proto)
smp_wmb();
nf_ct_protos[l4proto->l3proto] = proto_array;
- } else if (nf_ct_protos[l4proto->l3proto][l4proto->l4proto] !=
- &nf_conntrack_l4proto_generic) {
+ } else if (rcu_dereference_protected(
+ nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
+ lockdep_is_held(&nf_ct_proto_mutex)
+ ) != &nf_conntrack_l4proto_generic) {
ret = -EBUSY;
goto out_unlock;
}
@@ -331,7 +338,10 @@ void nf_conntrack_l4proto_unregister(struct nf_conntrack_l4proto *l4proto)
BUG_ON(l4proto->l3proto >= PF_MAX);
mutex_lock(&nf_ct_proto_mutex);
- BUG_ON(nf_ct_protos[l4proto->l3proto][l4proto->l4proto] != l4proto);
+ BUG_ON(rcu_dereference_protected(
+ nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
+ lockdep_is_held(&nf_ct_proto_mutex)
+ ) != l4proto);
rcu_assign_pointer(nf_ct_protos[l4proto->l3proto][l4proto->l4proto],
&nf_conntrack_l4proto_generic);
nf_ct_l4proto_unregister_sysctl(l4proto);
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 0fb6570..328f1d2 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -29,6 +29,7 @@
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_zones.h>
+#include <linux/rculist_nulls.h>
MODULE_LICENSE("GPL");
@@ -56,7 +57,7 @@ static struct hlist_nulls_node *ct_get_first(struct seq_file *seq)
for (st->bucket = 0;
st->bucket < net->ct.htable_size;
st->bucket++) {
- n = rcu_dereference(net->ct.hash[st->bucket].first);
+ n = rcu_dereference(hlist_nulls_first_rcu(&net->ct.hash[st->bucket]));
if (!is_a_nulls(n))
return n;
}
@@ -69,13 +70,15 @@ static struct hlist_nulls_node *ct_get_next(struct seq_file *seq,
struct net *net = seq_file_net(seq);
struct ct_iter_state *st = seq->private;
- head = rcu_dereference(head->next);
+ head = rcu_dereference(hlist_nulls_next_rcu(head));
while (is_a_nulls(head)) {
if (likely(get_nulls_value(head) == st->bucket)) {
if (++st->bucket >= net->ct.htable_size)
return NULL;
}
- head = rcu_dereference(net->ct.hash[st->bucket].first);
+ head = rcu_dereference(
+ hlist_nulls_first_rcu(
+ &net->ct.hash[st->bucket]));
}
return head;
}
diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index b07393e..20c775c 100644
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -161,7 +161,8 @@ static int seq_show(struct seq_file *s, void *v)
struct nf_logger *t;
int ret;
- logger = nf_loggers[*pos];
+ logger = rcu_dereference_protected(nf_loggers[*pos],
+ lockdep_is_held(&nf_log_mutex));
if (!logger)
ret = seq_printf(s, "%2lld NONE (", *pos);
@@ -249,7 +250,8 @@ static int nf_log_proc_dostring(ctl_table *table, int write,
mutex_unlock(&nf_log_mutex);
} else {
mutex_lock(&nf_log_mutex);
- logger = nf_loggers[tindex];
+ logger = rcu_dereference_protected(nf_loggers[tindex],
+ lockdep_is_held(&nf_log_mutex));
if (!logger)
table->data = "NONE";
else
diff --git a/net/netfilter/nf_queue.c b/net/netfilter/nf_queue.c
index 74aebed..1876f74 100644
--- a/net/netfilter/nf_queue.c
+++ b/net/netfilter/nf_queue.c
@@ -27,14 +27,17 @@ static DEFINE_MUTEX(queue_handler_mutex);
int nf_register_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
{
int ret;
+ const struct nf_queue_handler *old;
if (pf >= ARRAY_SIZE(queue_handler))
return -EINVAL;
mutex_lock(&queue_handler_mutex);
- if (queue_handler[pf] == qh)
+ old = rcu_dereference_protected(queue_handler[pf],
+ lockdep_is_held(&queue_handler_mutex));
+ if (old == qh)
ret = -EEXIST;
- else if (queue_handler[pf])
+ else if (old)
ret = -EBUSY;
else {
rcu_assign_pointer(queue_handler[pf], qh);
@@ -49,11 +52,15 @@ EXPORT_SYMBOL(nf_register_queue_handler);
/* The caller must flush their queue before this */
int nf_unregister_queue_handler(u_int8_t pf, const struct nf_queue_handler *qh)
{
+ const struct nf_queue_handler *old;
+
if (pf >= ARRAY_SIZE(queue_handler))
return -EINVAL;
mutex_lock(&queue_handler_mutex);
- if (queue_handler[pf] && queue_handler[pf] != qh) {
+ old = rcu_dereference_protected(queue_handler[pf],
+ lockdep_is_held(&queue_handler_mutex));
+ if (old && old != qh) {
mutex_unlock(&queue_handler_mutex);
return -EINVAL;
}
@@ -73,7 +80,10 @@ void nf_unregister_queue_handlers(const struct nf_queue_handler *qh)
mutex_lock(&queue_handler_mutex);
for (pf = 0; pf < ARRAY_SIZE(queue_handler); pf++) {
- if (queue_handler[pf] == qh)
+ if (rcu_dereference_protected(
+ queue_handler[pf],
+ lockdep_is_held(&queue_handler_mutex)
+ ) == qh)
rcu_assign_pointer(queue_handler[pf], NULL);
}
mutex_unlock(&queue_handler_mutex);
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 6a1572b..91592da 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -874,19 +874,19 @@ static struct hlist_node *get_first(struct iter_state *st)
for (st->bucket = 0; st->bucket < INSTANCE_BUCKETS; st->bucket++) {
if (!hlist_empty(&instance_table[st->bucket]))
- return rcu_dereference_bh(instance_table[st->bucket].first);
+ return rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
}
return NULL;
}
static struct hlist_node *get_next(struct iter_state *st, struct hlist_node *h)
{
- h = rcu_dereference_bh(h->next);
+ h = rcu_dereference_bh(hlist_next_rcu(h));
while (!h) {
if (++st->bucket >= INSTANCE_BUCKETS)
return NULL;
- h = rcu_dereference_bh(instance_table[st->bucket].first);
+ h = rcu_dereference_bh(hlist_first_rcu(&instance_table[st->bucket]));
}
return h;
}
--
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