tree: https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git pidfd.pidfd_get_task head: fd3fd0b4eb17f0ef3605d7bfd85ef7c97b93ec61 commit: fd3fd0b4eb17f0ef3605d7bfd85ef7c97b93ec61 [2/2] mm: use pidfd_get_task() config: nios2-allyesconfig (attached as .config) compiler: nios2-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/brauner/linux.git/commit/... git remote add brauner https://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git git fetch --no-tags brauner pidfd.pidfd_get_task git checkout fd3fd0b4eb17f0ef3605d7bfd85ef7c97b93ec61 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=nios2 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 >>): mm/madvise.c: In function '__do_sys_process_madvise': 1241 | unsigned int f_flags; | ^~~~~~~ cc1: all warnings being treated as errors vim +/f_flags +1241 mm/madvise.c ecb8ac8b1f1469 Minchan Kim 2020-10-17 1230 ecb8ac8b1f1469 Minchan Kim 2020-10-17 1231 SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec, ecb8ac8b1f1469 Minchan Kim 2020-10-17 1232 size_t, vlen, int, behavior, unsigned int, flags) ecb8ac8b1f1469 Minchan Kim 2020-10-17 1233 { ecb8ac8b1f1469 Minchan Kim 2020-10-17 1234 ssize_t ret; ecb8ac8b1f1469 Minchan Kim 2020-10-17 1235 struct iovec iovstack[UIO_FASTIOV], iovec; ecb8ac8b1f1469 Minchan Kim 2020-10-17 1236 struct iovec *iov = iovstack; ecb8ac8b1f1469 Minchan Kim 2020-10-17 1237 struct iov_iter iter; ecb8ac8b1f1469 Minchan Kim 2020-10-17 1238 struct task_struct *task; ecb8ac8b1f1469 Minchan Kim 2020-10-17 1239 struct mm_struct *mm; ecb8ac8b1f1469 Minchan Kim 2020-10-17 1240 size_t total_len; ecb8ac8b1f1469 Minchan Kim 2020-10-17 @1241 unsigned int f_flags; :::::: The code at line 1241 was first introduced by commit :::::: ecb8ac8b1f146915aa6b96449b66dd48984caacc mm/madvise: introduce process_madvise() syscall: an external memory hinting API :::::: TO: Minchan Kim <minchan(a)kernel.org&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