tree: https://github.com/weiny2/linux-kernel.git lm-misc head: 8c385a87dc5cb4d98fa417d3dd9481f3fbe4c625 commit: 9bbedda97f815fb2b6478966706968af63c983c2 [7/8] arch/kmap_atomic: Consolidate duplicate code config: sparc-defconfig (attached as .config) compiler: sparc-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 9bbedda97f815fb2b6478966706968af63c983c2 # save the attached .config to linux build tree GCC_VERSION=9.3.0 make.cross ARCH=sparc If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from arch/sparc/mm/highmem.c:26: include/linux/highmem.h: In function 'kmap': include/linux/highmem.h:40:9: error: implicit declaration of function '__kmap'; did you mean 'kmap'? [-Werror=implicit-function-declaration] 40 | return __kmap(page); | ^~~~~~ | kmap include/linux/highmem.h:40:9: error: returning 'int' from a function with return type 'void *' makes pointer from integer without a cast [-Werror=int-conversion] 40 | return __kmap(page); | ^~~~~~~~~~~~ include/linux/highmem.h: In function 'kunmap': include/linux/highmem.h:48:3: error: 'return' with no value, in function returning non-void [-Werror=return-type] 48 | return; | ^~~~~~ include/linux/highmem.h:44:21: note: declared here 44 | static inline void *kunmap(struct page *page) | ^~~~~~ arch/sparc/mm/highmem.c: In function 'kmap_atomic': 58 | unsigned long vaddr = __kmap_atomic(page); | ^~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +58 arch/sparc/mm/highmem.c 55 56 void *kmap_atomic(struct page *page) 57 { 59 long idx, type; 60 61 if (vaddr) 62 return (void *)vaddr; 63 64 type = kmap_atomic_idx_push(); 65 idx = type + KM_TYPE_NR*smp_processor_id(); 66 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); 67 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org