tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 585e5b17b92dead8a3aca4e3c9876fbca5f7e0ba commit: 0c86d774883fa17e7c81b0c8838b88d06c2c911e vdpasim: allow to assign a MAC address date: 2 weeks ago config: csky-randconfig-p002-20201113 (attached as .config) compiler: csky-linux-gcc (GCC) 9.3.0 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/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 0c86d774883fa17e7c81b0c8838b88d06c2c911e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=csky If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): csky-linux-ld: drivers/vdpa/vdpa_sim/vdpa_sim.o: in function `vdpasim_dev_init': vdpa_sim.c:(.init.text+0xc8): undefined reference to `mac_pton' csky-linux-ld: drivers/android/binder.o: in function `$t': binder.c:(.text+0x8cd4): undefined reference to `__get_user_bad' csky-linux-ld: binder.c:(.text+0x8de4): undefined reference to `__get_user_bad' csky-linux-ld: drivers/android/binder.o: in function `$d': binder.c:(.text+0x8e14): undefined reference to `__get_user_bad' csky-linux-ld: drivers/android/binder.o: in function `$t': binder.c:(.text+0x938e): undefined reference to `__get_user_bad' csky-linux-ld: binder.c:(.text+0x93b6): undefined reference to `__get_user_bad' csky-linux-ld: drivers/android/binder.o:binder.c:(.text+0x9430): more undefined references to `__get_user_bad' follow --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org