tree: https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git pending-4.19 head: da0ab6f9b4814a4a16e1999273d7dbd1a348314b commit: 145556839e5b22a724a2c7118e03a0531d844332 [47/61] ipv4: use dst hint for ipv4 list receive config: x86_64-randconfig-a002-20210620 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project d1baf2895467735ab14f4b3415fce204c0cc8e7f) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git/c... git remote add sashal-linux-stable https://git.kernel.org/pub/scm/linux/kernel/git/sashal/linux-stable.git git fetch --no-tags sashal-linux-stable pending-4.19 git checkout 145556839e5b22a724a2c7118e03a0531d844332 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): net/ipv4/ip_input.c:316:1: warning: declaration specifier missing, defaulting to 'int' INDIRECT_CALLABLE_DECLARE(int udp_v4_early_demux(struct sk_buff *)); ^ int net/ipv4/ip_input.c:317:1: warning: declaration specifier missing, defaulting to 'int' INDIRECT_CALLABLE_DECLARE(int tcp_v4_early_demux(struct sk_buff *)); ^ int net/ipv4/ip_input.c:343:10: error: implicit declaration of function 'INDIRECT_CALL_2' [-Werror,-Wimplicit-function-declaration] err = INDIRECT_CALL_2(edemux, tcp_v4_early_demux, ^ net/ipv4/ip_input.c:343:34: error: use of undeclared identifier 'tcp_v4_early_demux' err = INDIRECT_CALL_2(edemux, tcp_v4_early_demux, ^ net/ipv4/ip_input.c:344:12: error: use of undeclared identifier 'udp_v4_early_demux' udp_v4_early_demux, skb); ^ if (fib4_has_custom_rules(net) || rt_type == RTN_BROADCAST) ^ 2 warnings and 4 errors generated. vim +/fib4_has_custom_rules +564 net/ipv4/ip_input.c 560 561 static struct sk_buff *ip_extract_route_hint(const struct net *net, 562 struct sk_buff *skb, int rt_type) 563 { 565 return NULL; 566 567 return skb; 568 } 569 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org