tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.4.y head: 95a3867e897abd7811196123f81a119a75aba863 commit: 23f53171bec2190d3bda773b93281531235e83a6 [8047/9999] powerpc/book3s/32: fix number of bats in p/v_block_mapped() config: powerpc-mpc834x_mds_defconfig (attached as .config) compiler: powerpc-linux-gcc (GCC) 7.5.0 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://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.gi... git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git fetch --no-tags linux-stable-rc linux-4.4.y git checkout 23f53171bec2190d3bda773b93281531235e83a6 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-7.5.0 make.cross 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 >>): In file included from arch/powerpc/mm/ppc_mmu_32.c:26:0: include/linux/mm.h: In function 'is_vmalloc_addr': include/linux/mm.h:386:14: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] return addr >= VMALLOC_START && addr < VMALLOC_END; ^~ arch/powerpc/mm/ppc_mmu_32.c: At top level: arch/powerpc/mm/ppc_mmu_32.c:52:13: error: no previous prototype for 'v_mapped_by_bats' [-Werror=missing-prototypes] phys_addr_t v_mapped_by_bats(unsigned long va) ^~~~~~~~~~~~~~~~ arch/powerpc/mm/ppc_mmu_32.c: In function 'v_mapped_by_bats': for (b = 0; b < ARRAY_SIZE(bat_addrs); ++b) ^ arch/powerpc/mm/ppc_mmu_32.c: At top level: arch/powerpc/mm/ppc_mmu_32.c:64:15: error: no previous prototype for 'p_mapped_by_bats' [-Werror=missing-prototypes] unsigned long p_mapped_by_bats(phys_addr_t pa) ^~~~~~~~~~~~~~~~ arch/powerpc/mm/ppc_mmu_32.c: In function 'p_mapped_by_bats': arch/powerpc/mm/ppc_mmu_32.c:67:16: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare] for (b = 0; b < ARRAY_SIZE(bat_addrs); ++b) ^ cc1: all warnings being treated as errors vim +55 arch/powerpc/mm/ppc_mmu_32.c 48 49 /* 50 * Return PA for this VA if it is mapped by a BAT, or 0 51 */ 52 phys_addr_t v_mapped_by_bats(unsigned long va) 53 { 54 int b; 56 if (va >= bat_addrs[b].start && va < bat_addrs[b].limit) 57 return bat_addrs[b].phys + (va - bat_addrs[b].start); 58 return 0; 59 } 60 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org