Hi "Rafał,

I love your patch! Perhaps something to improve:

[auto build test WARNING on driver-core/driver-core-testing]
[also build test WARNING on char-misc/char-misc-testing linux/master linus/master v5.16-rc6 next-20211220]
[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/Rafa-Mi-ecki/sysfs-add-sysfs_add_bin_file_to_group/20211220-144856
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git aa483f3ce655ed9ee4f32d050d1822eec2d20ada
config: x86_64-randconfig-s021-20211219 (https://download.01.org/0day-ci/archive/20211221/202112210456.vwGC0F3M-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/a9802080b6d35af5dfd7ae847a0978e47caafd59
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Rafa-Mi-ecki/sysfs-add-sysfs_add_bin_file_to_group/20211220-144856
        git checkout a9802080b6d35af5dfd7ae847a0978e47caafd59
        # save the config file to linux build tree
        mkdir build_dir
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=x86_64 SHELL=/bin/bash fs/sysfs/

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


sparse warnings: (new ones prefixed by >>)
>> fs/sysfs/file.c:379:5: sparse: sparse: symbol '__sysfs_add_file_to_group' was not declared. Should it be static?

Please review and possibly fold the followup patch.

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