summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorFlorian Westphal <fw@strlen.de>2023-10-20 15:38:15 +0300
committerPablo Neira Ayuso <pablo@netfilter.org>2023-10-24 14:16:30 +0300
commit643d1260366424412e8269caead410d333e3263f (patch)
tree343e61c28953acb82bce302e442c54e72e3d1939
parentee6f05dcd6727669b6f49a8a6dafad94a40ee872 (diff)
downloadlinux-643d1260366424412e8269caead410d333e3263f.tar.xz
netfilter: conntrack: switch connlabels to atomic_t
The spinlock is back from the day when connabels did not have a fixed size and reallocation had to be supported. Remove it. This change also allows to call the helpers from softirq or timers without deadlocks. Also add WARN()s to catch refcounting imbalances. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
-rw-r--r--include/net/netfilter/nf_conntrack_labels.h2
-rw-r--r--include/net/netns/conntrack.h2
-rw-r--r--net/netfilter/nf_conntrack_labels.c17
3 files changed, 10 insertions, 11 deletions
diff --git a/include/net/netfilter/nf_conntrack_labels.h b/include/net/netfilter/nf_conntrack_labels.h
index fcb19a4e8f2b..6903f72bcc15 100644
--- a/include/net/netfilter/nf_conntrack_labels.h
+++ b/include/net/netfilter/nf_conntrack_labels.h
@@ -39,7 +39,7 @@ static inline struct nf_conn_labels *nf_ct_labels_ext_add(struct nf_conn *ct)
#ifdef CONFIG_NF_CONNTRACK_LABELS
struct net *net = nf_ct_net(ct);
- if (net->ct.labels_used == 0)
+ if (atomic_read(&net->ct.labels_used) == 0)
return NULL;
return nf_ct_ext_add(ct, NF_CT_EXT_LABELS, GFP_ATOMIC);
diff --git a/include/net/netns/conntrack.h b/include/net/netns/conntrack.h
index 1f463b3957c7..bae914815aa3 100644
--- a/include/net/netns/conntrack.h
+++ b/include/net/netns/conntrack.h
@@ -107,7 +107,7 @@ struct netns_ct {
struct nf_ct_event_notifier __rcu *nf_conntrack_event_cb;
struct nf_ip_net nf_ct_proto;
#if defined(CONFIG_NF_CONNTRACK_LABELS)
- unsigned int labels_used;
+ atomic_t labels_used;
#endif
};
#endif
diff --git a/net/netfilter/nf_conntrack_labels.c b/net/netfilter/nf_conntrack_labels.c
index 6e70e137a0a6..6c46aad23313 100644
--- a/net/netfilter/nf_conntrack_labels.c
+++ b/net/netfilter/nf_conntrack_labels.c
@@ -11,8 +11,6 @@
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_labels.h>
-static DEFINE_SPINLOCK(nf_connlabels_lock);
-
static int replace_u32(u32 *address, u32 mask, u32 new)
{
u32 old, tmp;
@@ -60,23 +58,24 @@ EXPORT_SYMBOL_GPL(nf_connlabels_replace);
int nf_connlabels_get(struct net *net, unsigned int bits)
{
+ int v;
+
if (BIT_WORD(bits) >= NF_CT_LABELS_MAX_SIZE / sizeof(long))
return -ERANGE;
- spin_lock(&nf_connlabels_lock);
- net->ct.labels_used++;
- spin_unlock(&nf_connlabels_lock);
-
BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE / sizeof(long) >= U8_MAX);
+ v = atomic_inc_return_relaxed(&net->ct.labels_used);
+ WARN_ON_ONCE(v <= 0);
+
return 0;
}
EXPORT_SYMBOL_GPL(nf_connlabels_get);
void nf_connlabels_put(struct net *net)
{
- spin_lock(&nf_connlabels_lock);
- net->ct.labels_used--;
- spin_unlock(&nf_connlabels_lock);
+ int v = atomic_dec_return_relaxed(&net->ct.labels_used);
+
+ WARN_ON_ONCE(v < 0);
}
EXPORT_SYMBOL_GPL(nf_connlabels_put);