Hi Christophe, I love your patch! Yet something to improve: [auto build test ERROR on hnaz-mm/master] url: https://github.com/0day-ci/linux/commits/Christophe-Leroy/mm-Outline-copy_overflow/20220207-190441 base: https://github.com/hnaz/linux-mm master config: i386-randconfig-a013-20220207 (https://download.01.org/0day-ci/archive/20220207/202202072148.OAzMGrDo-lkp@xxxxxxxxx/config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/2ae7547d08e23e529db61b3de0cb93879630a102 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christophe-Leroy/mm-Outline-copy_overflow/20220207-190441 git checkout 2ae7547d08e23e529db61b3de0cb93879630a102 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 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: "copy_overflow" [drivers/usb/gadget/function/usb_f_fs.ko] undefined! >> ERROR: modpost: "copy_overflow" [drivers/scsi/sg.ko] undefined! --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx