CC       csum
csum.c: In function 'recv_get_packet_csum_status':
csum.c:710:50: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'} [-Wformat=]
  710 |                         error(1, 0, "cmsg: len=%lu expected=%lu",
      |                                                ~~^
      |                                                  |
      |                                                  long unsigned int
      |                                                %u
  711 |                               cm->cmsg_len, CMSG_LEN(sizeof(struct tpacket_auxdata)));
      |                               ~~~~~~~~~~~~
      |                                 |
      |                                 size_t {aka unsigned int}
csum.c:710:63: warning: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'unsigned int' [-Wformat=]
  710 |                         error(1, 0, "cmsg: len=%lu expected=%lu",
      |                                                             ~~^
      |                                                               |
      |                                                               long unsigned int
      |                                                             %u

Correct format from %lu to %u for both.

Fixes: 91a7de85600d ("selftests/net: add csum offload test")
Signed-off-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>
---
 tools/testing/selftests/net/lib/csum.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/lib/csum.c b/tools/testing/selftests/net/lib/csum.c
index 27437590eeb53..9bcd7394b3043 100644
--- a/tools/testing/selftests/net/lib/csum.c
+++ b/tools/testing/selftests/net/lib/csum.c
@@ -707,7 +707,7 @@ static uint32_t recv_get_packet_csum_status(struct msghdr *msg)
 			      cm->cmsg_level, cm->cmsg_type);
 
 		if (cm->cmsg_len != CMSG_LEN(sizeof(struct tpacket_auxdata)))
-			error(1, 0, "cmsg: len=%lu expected=%lu",
+			error(1, 0, "cmsg: len=%u expected=%u",
 			      cm->cmsg_len, CMSG_LEN(sizeof(struct tpacket_auxdata)));
 
 		aux = (void *)CMSG_DATA(cm);
-- 
2.49.0

On Tue, 13 Jan 2026 18:44:19 +0100 Christophe Leroy (CS GROUP) wrote:
> csum.c:710:50: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' {aka 'unsigned int'} [-Wformat=]

> Correct format from %lu to %u for both.

I mean.. you're going to make the warning appear on every platform
which has a ulong size_t. I think you're looking for %zu?

> Fixes: 91a7de85600d ("selftests/net: add csum offload test")

No Fixes tags on trivial code cleanups please.