tree: https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git kspp/memcpy/next-20210618/v0 head: fd2aa2a169de8bde9502e7a2fc48cd03d4bfd996 commit: 245fccabb5777708f67afa04fc6b99a3f794986f [54/82] lib/string: Move helper functions out of string.c config: s390-randconfig-r034-20210618 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project d1baf2895467735ab14f4b3415fce204c0cc8e7f) 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 # install s390 cross compiling tool for clang build # apt-get install binutils-s390x-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git/commit/?id... git remote add kees https://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git git fetch --no-tags kees kspp/memcpy/next-20210618/v0 git checkout 245fccabb5777708f67afa04fc6b99a3f794986f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from arch/s390/boot/string.c:7: #define __NO_FORTIFY ^ <command line>:4:9: note: previous definition is here #define __NO_FORTIFY 1 ^ 1 warning generated. -- In file included from arch/s390/boot/string.c:7: #define __NO_FORTIFY ^ <command line>:5:9: note: previous definition is here #define __NO_FORTIFY 1 ^ 1 warning generated. vim +/__NO_FORTIFY +11 arch/s390/boot/../lib/string.c 12 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org