tree: https://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux-block.git for-next head: b85f8b070de4705a562e76162bb299ae9cdbca3b commit: 4633c45b49f2ba51f6688ac2aef6f74a25fcb433 [13/14] Merge branch 'for-5.6/io_uring-vfs' into for-next config: nds32-defconfig (attached as .config) compiler: nds32le-linux-gcc (GCC) 9.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 4633c45b49f2ba51f6688ac2aef6f74a25fcb433 # save the attached .config to linux build tree GCC_VERSION=9.2.0 make.cross ARCH=nds32 If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): fs/io_uring.c: In function 'io_epoll_ctl': 2661 | req->work.flags |= IO_WQ_WORK_NEEDS_FILES; | ^~~~~~~~~~~~~~~~~~~~~~ fs/io_uring.c:2661:22: note: each undeclared identifier is reported only once for each function it appears in vim +/IO_WQ_WORK_NEEDS_FILES +2661 fs/io_uring.c 6adb44effcb097 Jens Axboe 2020-01-08 2651 6adb44effcb097 Jens Axboe 2020-01-08 2652 static int io_epoll_ctl(struct io_kiocb *req, struct io_kiocb **nxt, 6adb44effcb097 Jens Axboe 2020-01-08 2653 bool force_nonblock) 6adb44effcb097 Jens Axboe 2020-01-08 2654 { 6adb44effcb097 Jens Axboe 2020-01-08 2655 #if defined(CONFIG_EPOLL) 6adb44effcb097 Jens Axboe 2020-01-08 2656 struct io_epoll *ie = &req->epoll; 6adb44effcb097 Jens Axboe 2020-01-08 2657 int ret; 6adb44effcb097 Jens Axboe 2020-01-08 2658 6adb44effcb097 Jens Axboe 2020-01-08 2659 ret = do_epoll_ctl(ie->epfd, ie->op, ie->fd, &ie->event, force_nonblock); 6adb44effcb097 Jens Axboe 2020-01-08 2660 if (force_nonblock && ret == -EAGAIN) { 6adb44effcb097 Jens Axboe 2020-01-08 @2661 req->work.flags |= IO_WQ_WORK_NEEDS_FILES; 6adb44effcb097 Jens Axboe 2020-01-08 2662 return -EAGAIN; 6adb44effcb097 Jens Axboe 2020-01-08 2663 } 6adb44effcb097 Jens Axboe 2020-01-08 2664 6adb44effcb097 Jens Axboe 2020-01-08 2665 if (ret < 0) 6adb44effcb097 Jens Axboe 2020-01-08 2666 req_set_fail_links(req); 6adb44effcb097 Jens Axboe 2020-01-08 2667 io_cqring_add_event(req, ret); 6adb44effcb097 Jens Axboe 2020-01-08 2668 io_put_req_find_next(req, nxt); 6adb44effcb097 Jens Axboe 2020-01-08 2669 return 0; 6adb44effcb097 Jens Axboe 2020-01-08 2670 #else 6adb44effcb097 Jens Axboe 2020-01-08 2671 return -EOPNOTSUPP; 6adb44effcb097 Jens Axboe 2020-01-08 2672 #endif 6adb44effcb097 Jens Axboe 2020-01-08 2673 } 6adb44effcb097 Jens Axboe 2020-01-08 2674 :::::: The code at line 2661 was first introduced by commit :::::: 6adb44effcb0979a6ba8fa0fddcd26fd4f33efa0 io_uring: add support for epoll_ctl(2) :::::: TO: Jens Axboe <axboe(a)kernel.dk&gt; :::::: CC: Jens Axboe <axboe(a)kernel.dk&gt; --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation