Hi Christophe, I love your patch! Perhaps something to improve: [auto build test WARNING on powerpc/next] [also build test WARNING on linus/master v5.13-rc1 next-20210512] [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/Christophe-Leroy/kprobes-Allow-a... base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: powerpc-allyesconfig (attached as .config) compiler: powerpc64-linux-gcc (GCC) 9.3.0 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/1cc4bb503e4ee4839247b767883c8b860... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christophe-Leroy/kprobes-Allow-architectures-to-override-optinsn-page-allocation/20210512-223121 git checkout 1cc4bb503e4ee4839247b767883c8b860b26413c # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross W=1 ARCH=powerpc 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 >>): 36 | void *alloc_optinsn_page(void) | ^~~~~~~~~~~~~~~~~~ 44 | void free_optinsn_page(void *page) | ^~~~~~~~~~~~~~~~~ vim +/alloc_optinsn_page +36 arch/powerpc/kernel/optprobes.c 35 37 { 38 if (insn_page_in_use) 39 return NULL; 40 insn_page_in_use = true; 41 return &optinsn_slot; 42 } 43 45 { 46 insn_page_in_use = false; 47 } 48 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org