Hi Tong, Thank you for the patch! Yet something to improve: [auto build test ERROR on linus/master] [also build test ERROR on v5.17-rc1 next-20220124] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Tong-Zhang/binfmt_misc-fix-crash... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git dd81e1c7d5fb126e5fbc5c9e334d7b3ec29a16a0 config: arm-randconfig-c002-20220124 (https://download.01.org/0day-ci/archive/20220124/202201242006.cqM8NznF-lk...) compiler: arm-linux-gnueabi-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/0day-ci/linux/commit/d649008f3214eb4d94760873831ef5e53... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Tong-Zhang/binfmt_misc-fix-crash-when-load-unload-module/20220124-083500 git checkout d649008f3214eb4d94760873831ef5e53c292976 # 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=arm SHELL=/bin/bash 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 >>): fs/binfmt_misc.c: In function 'init_misc_binfmt': 828 | binfmt_misc_header = register_sysctl_mount_point("fs/binfmt_misc"); | ^ cc1: some warnings being treated as errors vim +828 fs/binfmt_misc.c 821 822 static int __init init_misc_binfmt(void) 823 { 824 int err = register_filesystem(&bm_fs_type); 825 if (!err) 826 insert_binfmt(&misc_format); 827 829 if (!binfmt_misc_header) { 830 pr_warn("Failed to create fs/binfmt_misc sysctl mount point"); 831 return -ENOMEM; 832 } 833 return 0; 834 } 835 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org