[congwang:sch_bpf 3/3] ERROR: modpost: "qdisc_lookup_rcu" [net/sched/sch_bpf.ko] undefined!

[kernel test robot]

tree:   https://github.com/congwang/linux.git sch_bpf
head:   5fb0da1e47e0c68da0323a3e0399b2628a13e999
commit: 5fb0da1e47e0c68da0323a3e0399b2628a13e999 [3/3] net_sched: introduce eBPF based Qdisc
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20211229/202112292229.XxqsKDIS-lkp@xxxxxxxxx/config)
compiler: m68k-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
        # https://github.com/congwang/linux/commit/5fb0da1e47e0c68da0323a3e0399b2628a13e999
        git remote add congwang https://github.com/congwang/linux.git
        git fetch --no-tags congwang sch_bpf
        git checkout 5fb0da1e47e0c68da0323a3e0399b2628a13e999
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=m68k SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "qdisc_lookup_rcu" [net/sched/sch_bpf.ko] undefined!

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0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx