tree: https://github.com/zen-kernel/zen-kernel 5.13/futex2-tkg head: 8eb940ffa39f19c4ddf284615dfb27a6444a3c1d commit: afe010e85ccec03a8bbfafdf9687248386e7fd39 [14/15] futex2: Add sysfs entry for syscall numbers config: sh-randconfig-c004-20210720 (attached as .config) compiler: sh4-linux-gcc (GCC) 10.3.0 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/zen-kernel/zen-kernel/commit/afe010e85ccec03a8bbfafdf9... git remote add zen-kernel-zen-kernel https://github.com/zen-kernel/zen-kernel git fetch --no-tags zen-kernel-zen-kernel 5.13/futex2-tkg git checkout afe010e85ccec03a8bbfafdf9687248386e7fd39 # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross O=build_dir ARCH=sh SHELL=/bin/bash 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 >>): kernel/futex2.c: In function 'wait_show': 1230 | return sprintf(buf, "%u\n", __NR_futex_wait); | ^~~~~~~~~~~~~~~ | __futex_wait kernel/futex2.c:1230:30: note: each undeclared identifier is reported only once for each function it appears in kernel/futex2.c: In function 'wake_show': 1238 | return sprintf(buf, "%u\n", __NR_futex_wake); | ^~~~~~~~~~~~~~~ | ksys_futex_wake kernel/futex2.c: In function 'waitv_show': 1246 | return sprintf(buf, "%u\n", __NR_futex_waitv); | ^~~~~~~~~~~~~~~~ | __futex_wait kernel/futex2.c:1248:1: error: control reaches end of non-void function [-Werror=return-type] 1248 | } | ^ kernel/futex2.c: In function 'wake_show': kernel/futex2.c:1240:1: error: control reaches end of non-void function [-Werror=return-type] 1240 | } | ^ kernel/futex2.c: In function 'wait_show': kernel/futex2.c:1232:1: error: control reaches end of non-void function [-Werror=return-type] 1232 | } | ^ cc1: some warnings being treated as errors vim +1230 kernel/futex2.c 1226 1227 static ssize_t wait_show(struct kobject *kobj, struct kobj_attribute *attr, 1228 char *buf) 1229 { 1231 1232 } 1233 static struct kobj_attribute futex2_wait_attr = __ATTR_RO(wait); 1234 1235 static ssize_t wake_show(struct kobject *kobj, struct kobj_attribute *attr, 1236 char *buf) 1237 { 1239 1240 } 1241 static struct kobj_attribute futex2_wake_attr = __ATTR_RO(wake); 1242 1243 static ssize_t waitv_show(struct kobject *kobj, struct kobj_attribute *attr, 1244 char *buf) 1245 { 1247 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org