Hi Christophe, I love your patch! Yet something to improve: [auto build test ERROR on powerpc/next] [also build test ERROR on hnaz-mm/master linus/master v5.16-rc2 next-20211118] [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/Convert-powerpc-to-default-topdown-mmap-layout/20211122-165115 base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: arm-randconfig-r005-20211122 (attached as .config) 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/e5949ff1a8e5cae8e9ac2ec3a39849bf2e73eb34 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Christophe-Leroy/Convert-powerpc-to-default-topdown-mmap-layout/20211122-165115 git checkout e5949ff1a8e5cae8e9ac2ec3a39849bf2e73eb34 # save the attached .config 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 All errors (new ones prefixed by >>): arm-linux-gnueabi-ld: fs/binfmt_elf.o: in function `load_elf_binary': >> binfmt_elf.c:(.text+0x16d8): undefined reference to `arch_randomize_brk' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org