[PATCH] netfilter: nf_flow_table_bpf: add prototype for bpf_xdp_flow_lookup()

[PATCH] netfilter: nf_flow_table_bpf: add prototype for bpf_xdp_flow_lookup()

[Sun Jian]

Sparse reports:

  netfilter/nf_flow_table_bpf.c:58:45:
    symbol 'bpf_xdp_flow_lookup' was not declared. Should it be static?

bpf_xdp_flow_lookup() is exported as a __bpf_kfunc and must remain
non-static. Add a forward declaration to provide an explicit prototype
, only to silence the sparse warning.

No functional change intended.

Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
---
 net/netfilter/nf_flow_table_bpf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/netfilter/nf_flow_table_bpf.c b/net/netfilter/nf_flow_table_bpf.c
index 4a5f5195f2d2..a129e0ee5e81 100644
--- a/net/netfilter/nf_flow_table_bpf.c
+++ b/net/netfilter/nf_flow_table_bpf.c
@@ -31,6 +31,9 @@ __diag_ignore_all("-Wmissing-prototypes",
 		  "Global functions as their definitions will be in nf_flow_table BTF");
 
 __bpf_kfunc_start_defs();
+__bpf_kfunc struct flow_offload_tuple_rhash *
+bpf_xdp_flow_lookup(struct xdp_md *ctx, struct bpf_fib_lookup *fib_tuple,
+		    struct bpf_flowtable_opts *opts, u32 opts_len);
 
 static struct flow_offload_tuple_rhash *
 bpf_xdp_flow_tuple_lookup(struct net_device *dev,
-- 
2.43.0

Re: [PATCH] netfilter: nf_flow_table_bpf: add prototype for bpf_xdp_flow_lookup()

[Alexei Starovoitov]

On Mon, Jan 19, 2026 at 1:16 AM Sun Jian <sun.jian.kdev@gmail.com> wrote:
>
> Sparse reports:
>
>   netfilter/nf_flow_table_bpf.c:58:45:
>     symbol 'bpf_xdp_flow_lookup' was not declared. Should it be static?
>
> bpf_xdp_flow_lookup() is exported as a __bpf_kfunc and must remain
> non-static. Add a forward declaration to provide an explicit prototype
> , only to silence the sparse warning.

No. Ignore the warning. Sparse is incorrect.
We have hundreds of such bogus warnings. Do NOT attempt to send
more patches to "fix" them.

pw-bot: cr