From: Simon Horman Date: Mon, 16 Sep 2024 15:14:41 +0000 (+0100) Subject: netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=e1f1ee0e9ad8cbe660f5c104e791c5f1a7cf4c31;p=linux-2.6-block.git netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS Only provide ctnetlink_label_size when it is used, which is when CONFIG_NF_CONNTRACK_EVENTS is configured. Flagged by clang-18 W=1 builds as: .../nf_conntrack_netlink.c:385:19: warning: unused function 'ctnetlink_label_size' [-Wunused-function] 385 | static inline int ctnetlink_label_size(const struct nf_conn *ct) | ^~~~~~~~~~~~~~~~~~~~ The condition on CONFIG_NF_CONNTRACK_LABELS being removed by this patch guards compilation of non-trivial implementations of ctnetlink_dump_labels() and ctnetlink_label_size(). However, this is not necessary as each of these functions will always return 0 if CONFIG_NF_CONNTRACK_LABELS is not defined as each function starts with the equivalent of: struct nf_conn_labels *labels = nf_ct_labels_find(ct); if (!labels) return 0; And nf_ct_labels_find always returns NULL if CONFIG_NF_CONNTRACK_LABELS is not enabled. So I believe that the compiler optimises the code away in such cases anyway. Found by inspection. Compile tested only. Originally splitted in two patches, Pablo Neira Ayuso collapsed them and added Fixes: tag. Fixes: 0ceabd83875b ("netfilter: ctnetlink: deliver labels to userspace") Link: https://lore.kernel.org/netfilter-devel/20240909151712.GZ2097826@kernel.org/ Signed-off-by: Simon Horman Signed-off-by: Pablo Neira Ayuso --- diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 8fd2b9e392a7..6a1239433830 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -382,7 +382,7 @@ nla_put_failure: #define ctnetlink_dump_secctx(a, b) (0) #endif -#ifdef CONFIG_NF_CONNTRACK_LABELS +#ifdef CONFIG_NF_CONNTRACK_EVENTS static inline int ctnetlink_label_size(const struct nf_conn *ct) { struct nf_conn_labels *labels = nf_ct_labels_find(ct); @@ -391,6 +391,7 @@ static inline int ctnetlink_label_size(const struct nf_conn *ct) return 0; return nla_total_size(sizeof(labels->bits)); } +#endif static int ctnetlink_dump_labels(struct sk_buff *skb, const struct nf_conn *ct) @@ -411,10 +412,6 @@ ctnetlink_dump_labels(struct sk_buff *skb, const struct nf_conn *ct) return 0; } -#else -#define ctnetlink_dump_labels(a, b) (0) -#define ctnetlink_label_size(a) (0) -#endif #define master_tuple(ct) &(ct->master->tuplehash[IP_CT_DIR_ORIGINAL].tuple)