From: kernel test robot <lkp@intel.com>
To: Irlanki Sandeep <irlanki.s@samsung.com>,
netdev@vger.kernel.org, bpf@vger.kernel.org
Cc: oe-kbuild-all@lists.linux.dev, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
ncardwell@google.com, ast@kernel.org, daniel@iogearbox.net,
andrii@kernel.org, corbet@lwn.net, linux-kernel@vger.kernel.org,
lorenzo@google.com, maze@google.com, sporeba@google.com,
motomuman@google.com, srihari.k@samsung.com,
g.pokhra@samsung.com, r.kumawat@samsung.com,
raj.kumars@samsung.com, ts413.lee@samsung.com,
Irlanki Sandeep <irlanki.s@samsung.com>
Subject: Re: [PATCH net-next] tcp: add TCP_ECN and TCP_ECN_OPTION socket options
Date: Thu, 10 Sep 2026 09:38:48 +0800 [thread overview]
Message-ID: <202609100957.cYRwpjGl-lkp@intel.com> (raw)
In-Reply-To: <20260909144557.800676-1-irlanki.s@samsung.com>
Hi Irlanki,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 548b86839f7fb819a4d6c83b71c73ec378d24275]
url: https://github.com/intel-lab-lkp/linux/commits/Irlanki-Sandeep/tcp-add-TCP_ECN-and-TCP_ECN_OPTION-socket-options/20260909-201557
base: 548b86839f7fb819a4d6c83b71c73ec378d24275
patch link: https://lore.kernel.org/r/20260909144557.800676-1-irlanki.s%40samsung.com
patch subject: [PATCH net-next] tcp: add TCP_ECN and TCP_ECN_OPTION socket options
config: i386-randconfig-141-20260910 (https://download.01.org/0day-ci/archive/20260910/202609100957.cYRwpjGl-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.4.0-5) 12.4.0
smatch: v0.5.0-9187-g5189e3fb
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260910/202609100957.cYRwpjGl-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202609100957.cYRwpjGl-lkp@intel.com/
All warnings (new ones prefixed by >>):
net/ipv4/tcp_input.c: In function 'tcp_ecn_create_request':
>> net/ipv4/tcp_input.c:7460:27: warning: unused variable 'net' [-Wunused-variable]
7460 | const struct net *net = sock_net(listen_sk);
| ^~~
vim +/net +7460 net/ipv4/tcp_input.c
1fb6f159fd21c64 Octavian Purdila 2014-06-25 7436
d82bd1229885d55 Florian Westphal 2014-09-29 7437 /* RFC3168 : 6.1.1 SYN packets must not have ECT/ECN bits set
d82bd1229885d55 Florian Westphal 2014-09-29 7438 *
d82bd1229885d55 Florian Westphal 2014-09-29 7439 * If we receive a SYN packet with these bits set, it means a
d82bd1229885d55 Florian Westphal 2014-09-29 7440 * network is playing bad games with TOS bits. In order to
d82bd1229885d55 Florian Westphal 2014-09-29 7441 * avoid possible false congestion notifications, we disable
f4e715c3254e3c0 stephen hemminger 2014-10-29 7442 * TCP ECN negotiation.
d82bd1229885d55 Florian Westphal 2014-09-29 7443 *
d82bd1229885d55 Florian Westphal 2014-09-29 7444 * Exception: tcp_ca wants ECN. This is required for DCTCP
843c2fdf7a12951 Florian Westphal 2015-01-30 7445 * congestion control: Linux DCTCP asserts ECT on all packets,
843c2fdf7a12951 Florian Westphal 2015-01-30 7446 * including SYN, which is most optimal solution; however,
843c2fdf7a12951 Florian Westphal 2015-01-30 7447 * others, such as FreeBSD do not.
f6fee16dbbe3fe4 Tilmans, Olivier (Nokia - BE/Antwerp 2019-04-03 7448) *
f6fee16dbbe3fe4 Tilmans, Olivier (Nokia - BE/Antwerp 2019-04-03 7449) * Exception: At least one of the reserved bits of the TCP header (th->res1) is
f6fee16dbbe3fe4 Tilmans, Olivier (Nokia - BE/Antwerp 2019-04-03 7450) * set, indicating the use of a future TCP extension (such as AccECN). See
f6fee16dbbe3fe4 Tilmans, Olivier (Nokia - BE/Antwerp 2019-04-03 7451) * RFC8311 §4.3 which updates RFC3168 to allow the development of such
f6fee16dbbe3fe4 Tilmans, Olivier (Nokia - BE/Antwerp 2019-04-03 7452) * extensions.
d82bd1229885d55 Florian Westphal 2014-09-29 7453 */
d82bd1229885d55 Florian Westphal 2014-09-29 7454 static void tcp_ecn_create_request(struct request_sock *req,
d82bd1229885d55 Florian Westphal 2014-09-29 7455 const struct sk_buff *skb,
f7b3bec6f5167ef Florian Westphal 2014-11-03 7456 const struct sock *listen_sk,
f7b3bec6f5167ef Florian Westphal 2014-11-03 7457 const struct dst_entry *dst)
d82bd1229885d55 Florian Westphal 2014-09-29 7458 {
d82bd1229885d55 Florian Westphal 2014-09-29 7459 const struct tcphdr *th = tcp_hdr(skb);
d82bd1229885d55 Florian Westphal 2014-09-29 @7460 const struct net *net = sock_net(listen_sk);
d82bd1229885d55 Florian Westphal 2014-09-29 7461 bool th_ecn = th->ece && th->cwr;
843c2fdf7a12951 Florian Westphal 2015-01-30 7462 bool ect, ecn_ok;
c3a8d9474684d39 Daniel Borkmann 2015-08-31 7463 u32 ecn_ok_dst;
d82bd1229885d55 Florian Westphal 2014-09-29 7464
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7465 if (tcp_accecn_syn_requested(th) &&
4ea2ce8e35e36ab Irlanki Sandeep 2026-09-09 7466 (tcp_ecn_mode_eff(listen_sk) >= 3 ||
100f946b8d44b64 Chia-Yu Chang 2026-01-31 7467 tcp_ca_needs_accecn(listen_sk))) {
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7468 inet_rsk(req)->ecn_ok = 1;
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7469 tcp_rsk(req)->accecn_ok = 1;
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7470 tcp_rsk(req)->syn_ect_rcv = TCP_SKB_CB(skb)->ip_dsfield &
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7471 INET_ECN_MASK;
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7472 return;
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7473 }
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7474
d82bd1229885d55 Florian Westphal 2014-09-29 7475 if (!th_ecn)
d82bd1229885d55 Florian Westphal 2014-09-29 7476 return;
d82bd1229885d55 Florian Westphal 2014-09-29 7477
d82bd1229885d55 Florian Westphal 2014-09-29 7478 ect = !INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield);
c3a8d9474684d39 Daniel Borkmann 2015-08-31 7479 ecn_ok_dst = dst_feature(dst, DST_FEATURE_ECN_MASK);
4ea2ce8e35e36ab Irlanki Sandeep 2026-09-09 7480 ecn_ok = tcp_ecn_mode_eff(listen_sk) || ecn_ok_dst;
d82bd1229885d55 Florian Westphal 2014-09-29 7481
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7482 if (((!ect || th->res1 || th->ae) && ecn_ok) ||
3cae34274c79e0c Ilpo Järvinen 2025-09-16 7483 tcp_ca_needs_ecn(listen_sk) ||
91b5b21c7c16899 Lawrence Brakmo 2017-06-30 7484 (ecn_ok_dst & DST_FEATURE_ECN_CA) ||
91b5b21c7c16899 Lawrence Brakmo 2017-06-30 7485 tcp_bpf_ca_needs_ecn((struct sock *)req))
d82bd1229885d55 Florian Westphal 2014-09-29 7486 inet_rsk(req)->ecn_ok = 1;
d82bd1229885d55 Florian Westphal 2014-09-29 7487 }
d82bd1229885d55 Florian Westphal 2014-09-29 7488
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
prev parent reply other threads:[~2026-09-10 1:40 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20260909144437epcas5p282be513a761ca5aec3f2b0fefcd2ecfa@epcas5p2.samsung.com>
2026-09-09 14:45 ` Irlanki Sandeep
2026-09-10 1:38 ` kernel test robot [this message]
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