[asm-generic:asm-generic-uaccess-6 6/10] ERROR: modpost: "__copy_tofrom_user" [net/bridge/bridge.ko] undefined!

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git asm-generic-uaccess-6
head:   725a40b8ebf55a6b95e11a6b35717a99afc8ac98
commit: 8ea805cb5e3294c8890c4781f82c03d6cc417bf5 [6/10] microblaze: use generic strncpy/strnlen from_user
config: microblaze-mmu_defconfig (attached as .config)
compiler: microblaze-linux-gcc (GCC) 10.3.0
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://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git/commit/?id=8ea805cb5e3294c8890c4781f82c03d6cc417bf5
        git remote add asm-generic https://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic.git
        git fetch --no-tags asm-generic asm-generic-uaccess-6
        git checkout 8ea805cb5e3294c8890c4781f82c03d6cc417bf5
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross ARCH=microblaze 

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

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

quoted

ERROR: modpost: "__copy_tofrom_user" [net/bridge/bridge.ko] undefined!

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