From: Geliang Tang <tanggeliang@kylinos.cn>

Set the return value of tcp_sock_set_maxseg() to err.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
---
 net/ipv4/tcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 5aafe569d4d0..c8f31be4dfa9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3896,7 +3896,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
 
 	switch (optname) {
 	case TCP_MAXSEG:
-		tcp_sock_set_maxseg(sk, val);
+		err = tcp_sock_set_maxseg(sk, val);
 		break;
 
 	case TCP_NODELAY:
-- 
2.48.1

Hi Geliang,

On 17/07/2025 03:37, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> Set the return value of tcp_sock_set_maxseg() to err.

Good catch!

Now in our tree:

- 1250f401ac70: "squashed" in "tcp: add tcp_sock_set_maxseg"

New patches for t/upstream:
- 1250f401ac70: Squash to "tcp: add tcp_sock_set_maxseg"
- 4243d759a096: Squash to "mptcp: add TCP_MAXSEG sockopt support"
- Results: d196b0945719..eb948f761895 (export)

Tests are now in progress:

- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/4c4a8f3705b5a68dec06d5bdcbe08409aa15ab84/checks

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.

Hi Geliang,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Unstable: 1 failed test(s): selftest_mptcp_connect_checksum 🔴
- KVM Validation: debug: Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/16334182085

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/7792e3c7df02
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=983148


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)