tree: https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git 20211118-sysctl-cleanups-set-04-v2 head: 3110d41a56792588bd2f64621080948b0fceb6ab commit: 08083da6a8f2a955383155397792120ffc520978 [34/36] fs: move pipe sysctls to is own file config: nds32-allnoconfig (attached as .config) compiler: nds32le-linux-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://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git/com... git remote add mcgrof-next https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-next.git git fetch --no-tags mcgrof-next 20211118-sysctl-cleanups-set-04-v2 git checkout 08083da6a8f2a955383155397792120ffc520978 # 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=nds32 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 >>): fs/pipe.c:756:15: warning: no previous prototype for 'account_pipe_buffers' [-Wmissing-prototypes] 756 | unsigned long account_pipe_buffers(struct user_struct *user, | ^~~~~~~~~~~~~~~~~~~~ fs/pipe.c:762:6: warning: no previous prototype for 'too_many_pipe_buffers_soft' [-Wmissing-prototypes] 762 | bool too_many_pipe_buffers_soft(unsigned long user_bufs) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ fs/pipe.c:769:6: warning: no previous prototype for 'too_many_pipe_buffers_hard' [-Wmissing-prototypes] 769 | bool too_many_pipe_buffers_hard(unsigned long user_bufs) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ fs/pipe.c:776:6: warning: no previous prototype for 'pipe_is_unprivileged_user' [-Wmissing-prototypes] 776 | bool pipe_is_unprivileged_user(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~ fs/pipe.c:1246:5: warning: no previous prototype for 'pipe_resize_ring' [-Wmissing-prototypes] 1246 | int pipe_resize_ring(struct pipe_inode_info *pipe, unsigned int nr_slots) | ^~~~~~~~~~~~~~~~ fs/pipe.c: In function 'init_pipe_fs': 1498 | register_sysctl_init("fs", fs_pipe_sysctls, "pipe_sysctls"); | ^ In file included from include/linux/key.h:17, from include/linux/cred.h:13, from include/linux/sched/signal.h:10, from include/linux/rcuwait.h:6, from include/linux/percpu-rwsem.h:7, from include/linux/fs.h:33, from include/linux/huge_mm.h:8, from include/linux/mm.h:717, from fs/pipe.c:8: include/linux/sysctl.h:220: note: macro "register_sysctl_init" defined here 220 | #define register_sysctl_init(path, table) __register_sysctl_init(path, table, #table) | 1498 | register_sysctl_init("fs", fs_pipe_sysctls, "pipe_sysctls"); | ^~~~~~~~~~~~~~~~~~~~ | register_sysctl_paths fs/pipe.c:1498:9: note: each undeclared identifier is reported only once for each function it appears in At top level: fs/pipe.c:1460:25: warning: 'fs_pipe_sysctls' defined but not used [-Wunused-variable] 1460 | static struct ctl_table fs_pipe_sysctls[] = { | ^~~~~~~~~~~~~~~ vim +/register_sysctl_init +1498 fs/pipe.c 1485 1486 static int __init init_pipe_fs(void) 1487 { 1488 int err = register_filesystem(&pipe_fs_type); 1489 1490 if (!err) { 1491 pipe_mnt = kern_mount(&pipe_fs_type); 1492 if (IS_ERR(pipe_mnt)) { 1493 err = PTR_ERR(pipe_mnt); 1494 unregister_filesystem(&pipe_fs_type); 1495 } 1496 } 1497 #ifdef CONFIG_SYSCTL 1499 #endif 1500 return err; 1501 } 1502 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org