tree: https://github.com/multipath-tcp/mptcp_net-next.git export head: 8d79e486d97bbdec3af4cf2f19d91fec433d437b commit: 48c617e1584b3190eb02338f4ef77807f433e579 [24/34] mptcp: getsockopt: add support for IP_TOS config: um-i386_defconfig (https://download.01.org/0day-ci/archive/20211208/202112081738.D1IpgkU6-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/multipath-tcp/mptcp_net-next/commit/48c617e1584b3190eb... git remote add mptcp https://github.com/multipath-tcp/mptcp_net-next.git git fetch --no-tags mptcp export git checkout 48c617e1584b3190eb02338f4ef77807f433e579 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=um SUBARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): 1174 | static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname, | ^~~~~~~~~~~~~~~~~~~ net/mptcp/sockopt.c:1161:12: note: previous definition of 'mptcp_getsockopt_v4' was here 1161 | static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname, | ^~~~~~~~~~~~~~~~~~~ net/mptcp/sockopt.c:1161:12: warning: 'mptcp_getsockopt_v4' defined but not used [-Wunused-function] vim +/mptcp_getsockopt_v4 +1174 net/mptcp/sockopt.c 48c617e1584b31 Florian Westphal 2021-12-08 1173 3b1e21eb60e8d4 Florian Westphal 2021-12-03 @1174 static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname, 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1175 char __user *optval, int __user *optlen) 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1176 { 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1177 struct sock *sk = (void *)msk; 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1178 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1179 switch (optname) { 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1180 case IP_TOS: 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1181 return mptcp_put_int_option(msk, optval, optlen, inet_sk(sk)->tos); 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1182 } 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1183 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1184 return -EOPNOTSUPP; 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1185 } 3b1e21eb60e8d4 Florian Westphal 2021-12-03 1186 :::::: The code at line 1174 was first introduced by commit :::::: 3b1e21eb60e8d4aa42474fed606a8ea8767b0120 mptcp: getsockopt: add support for IP_TOS :::::: TO: Florian Westphal <fw(a)strlen.de&gt; :::::: CC: Jakub Kicinski <kuba(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org