6.1-stable review patch. If anyone has any objections, please let me know.
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From: Simon Horman horms@kernel.org
[ Upstream commit e1f1ee0e9ad8cbe660f5c104e791c5f1a7cf4c31 ]
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 horms@kernel.org Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_conntrack_netlink.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 9672b0e00d6bf..2cf58a8b8e4dc 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -381,7 +381,7 @@ static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct) #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); @@ -390,6 +390,7 @@ 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) @@ -410,10 +411,6 @@ 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)