Hi WingMan, FYI, the error/warning still remains. tree: git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git ti-linux-5.10.y head: f22103162c771ddd47372b579682445e6dc8dd0e commit: 89b354a68fd094a218c79af743e60299045f33b5 [7096/9684] net: socket: Pass on redundant net info to sock_recv_errqueue config: parisc-defconfig (attached as .config) compiler: hppa-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git remote add ti git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git git fetch --no-tags ti ti-linux-5.10.y git checkout 89b354a68fd094a218c79af743e60299045f33b5 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=parisc SHELL=/bin/bash net/ 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 >>): In file included from include/net/inet_sock.h:22, from include/net/ip.h:28, from include/linux/errqueue.h:6, from net/core/sock.c:91: include/net/sock.h: In function 'sock_recv_redundant_info': include/net/sock.h:2525:43: error: 'SCM_REDUNDANT' undeclared (first use in this function) 2525 | put_cmsg(msg, SOL_SOCKET, SCM_REDUNDANT, sizeof(*sred), sred); | ^~~~~~~~~~~~~ include/net/sock.h:2525:43: note: each undeclared identifier is reported only once for each function it appears in net/core/sock.c: In function 'sock_recv_errqueue': 3179 | put_cmsg(msg, SOL_SOCKET, SCM_REDUNDANT, sizeof(*sred), sred); | ^~~~~~~~~~~~~ vim +/SCM_REDUNDANT +3179 net/core/sock.c 3153 3154 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, 3155 int level, int type) 3156 { 3157 struct sock_exterr_skb *serr; 3158 struct sk_buff *skb; 3159 int copied, err; 3160 struct skb_redundant_info *sred; 3161 3162 err = -EAGAIN; 3163 skb = sock_dequeue_err_skb(sk); 3164 if (skb == NULL) 3165 goto out; 3166 3167 copied = skb->len; 3168 if (copied > len) { 3169 msg->msg_flags |= MSG_TRUNC; 3170 copied = len; 3171 } 3172 err = skb_copy_datagram_msg(skb, 0, msg, copied); 3173 if (err) 3174 goto out_free_skb; 3175 3176 sock_recv_timestamp(msg, sk, skb); 3177 3178 sred = skb_redinfo(skb); 3180 3181 serr = SKB_EXT_ERR(skb); 3182 put_cmsg(msg, level, type, sizeof(serr->ee), &serr->ee); 3183 3184 msg->msg_flags |= MSG_ERRQUEUE; 3185 err = copied; 3186 3187 out_free_skb: 3188 kfree_skb(skb); 3189 out: 3190 return err; 3191 } 3192 EXPORT_SYMBOL(sock_recv_errqueue); 3193 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org