Hi Steve, First bad commit (maybe != root cause): tree: https://github.com/AsahiLinux/linux tipd/v2 head: 33646424fbe83c154fa7bfee199e261631e445ed commit: b4a8c8f8fa8b7b86bb62257fbb27e7bde58ac97e [1497/2972] cifs: rename fs/cifs directory to fs/smbfs_client config: nios2-allyesconfig (attached as .config) compiler: nios2-linux-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/AsahiLinux/linux/commit/b4a8c8f8fa8b7b86bb62257fbb27e7... git remote add asahilinux https://github.com/AsahiLinux/linux git fetch --no-tags asahilinux tipd/v2 git checkout b4a8c8f8fa8b7b86bb62257fbb27e7bde58ac97e # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=nios2 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 >>): 83 | int __init cifs_root_data(char **dev, char **opts) | ^~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/cifs_root_data +83 fs/smbfs_client/cifsroot.c 8eecd1c2e5bc73 fs/cifs/cifsroot.c Paulo Alcantara (SUSE 2019-07-16 82) 8eecd1c2e5bc73 fs/cifs/cifsroot.c Paulo Alcantara (SUSE 2019-07-16 @83) int __init cifs_root_data(char **dev, char **opts) :::::: The code at line 83 was first introduced by commit :::::: 8eecd1c2e5bc73d33f3a544751305679dbf88eb4 cifs: Add support for root file systems :::::: TO: Paulo Alcantara (SUSE) <paulo(a)paulo.ac&gt; :::::: CC: Steve French <stfrench(a)microsoft.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org