Hi Christophe, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 78e709522d2c012cb0daad2e668506637bffb7c2 commit: b26e8f27253a47bff90972b987112fd8396e9b8d powerpc/mem: Move cache flushing functions into mm/cacheflush.c date: 5 months ago config: powerpc-randconfig-s032-20210912 (attached as .config) compiler: powerpc64-linux-gcc (GCC) 11.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.4-dirty # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout b26e8f27253a47bff90972b987112fd8396e9b8d # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=powerpc 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 >>): 53 | int __weak create_section_mapping(unsigned long start, unsigned long end, | ^~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/create_section_mapping +53 arch/powerpc/mm/mem.c bc02af93dd2bbd Yasunori Goto 2006-06-27 52 4e00c5affdd4b0 Logan Gunthorpe 2020-04-10 @53 int __weak create_section_mapping(unsigned long start, unsigned long end, 4e00c5affdd4b0 Logan Gunthorpe 2020-04-10 54 int nid, pgprot_t prot) fecbfabe1dc940 Benjamin Herrenschmidt 2016-07-05 55 { fecbfabe1dc940 Benjamin Herrenschmidt 2016-07-05 56 return -ENODEV; fecbfabe1dc940 Benjamin Herrenschmidt 2016-07-05 57 } fecbfabe1dc940 Benjamin Herrenschmidt 2016-07-05 58 :::::: The code at line 53 was first introduced by commit :::::: 4e00c5affdd4b04e6392001716333971932f3d0c powerpc/mm: thread pgprot_t through create_section_mapping() :::::: TO: Logan Gunthorpe <logang(a)deltatee.com&gt; :::::: CC: Linus Torvalds <torvalds(a)linux-foundation.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org