diff mbox series

[net,09/14] netfilter: ctnetlink: compile ctnetlink_label_size with CONFIG_NF_CONNTRACK_EVENTS

Message ID 20240926110717.102194-10-pablo@netfilter.org (mailing list archive)
State Accepted
Commit e1f1ee0e9ad8cbe660f5c104e791c5f1a7cf4c31
Delegated to: Netdev Maintainers
Headers show
Series [net,01/14] netfilter: nf_nat: don't try nat source port reallocation for reverse dir clash | expand

Checks

Context Check Description
netdev/series_format success Pull request is its own cover letter
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 7 maintainers not CCed: justinstitt@google.com coreteam@netfilter.org kadlec@netfilter.org llvm@lists.linux.dev morbo@google.com ndesaulniers@google.com nathan@kernel.org
netdev/build_clang success Errors and warnings before: 16 this patch: 16
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 17 this patch: 17
netdev/checkpatch warning WARNING: 'splitted' may be misspelled - perhaps 'split'?
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Pablo Neira Ayuso Sept. 26, 2024, 11:07 a.m. UTC 
From: Simon Horman <horms@kernel.org>

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>
---
 net/netfilter/nf_conntrack_netlink.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)
diff mbox series

Patch

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 @@  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);
@@ -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)