Hi Mike, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on vhost/linux-next] [also build test WARNING on linux/master linus/master v5.13-rc7] [cannot apply to next-20210623] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Mike-Christie/kthread-pass-in-us... base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next config: riscv-randconfig-s032-20210622 (attached as .config) compiler: riscv64-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 # apt-get install sparse # sparse version: v0.6.3-341-g8af24329-dirty # https://github.com/0day-ci/linux/commit/daae0f4bb5ef7264d67cab20da3719275... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Mike-Christie/kthread-pass-in-user-and-check-RLIMIT_NPROC/20210624-110925 git checkout daae0f4bb5ef7264d67cab20da37192754f885b8 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) vim +599 drivers/vhost/vhost.c 581 582 /* Caller should have device mutex */ 583 long vhost_dev_set_owner(struct vhost_dev *dev) 584 { 585 struct task_struct *worker; 586 int err; 587 588 /* Is there an owner already? */ 589 if (vhost_dev_has_owner(dev)) { 590 err = -EBUSY; 591 goto err_mm; 592 } 593 594 vhost_attach_mm(dev); 595 596 dev->kcov_handle = kcov_common_handle(); 597 if (dev->use_worker) { 598 worker = kthread_create_for_user(vhost_worker, dev, 600 "vhost-%d", current->pid); 601 if (IS_ERR(worker)) { 602 err = PTR_ERR(worker); 603 goto err_worker; 604 } 605 606 dev->worker = worker; 607 wake_up_process(worker); /* avoid contributing to loadavg */ 608 609 err = vhost_attach_cgroups(dev); 610 if (err) 611 goto err_cgroup; 612 } 613 614 err = vhost_dev_alloc_iovecs(dev); 615 if (err) 616 goto err_cgroup; 617 618 return 0; 619 err_cgroup: 620 if (dev->worker) { 621 kthread_stop(dev->worker); 622 dev->worker = NULL; 623 } 624 err_worker: 625 vhost_detach_mm(dev); 626 dev->kcov_handle = 0; 627 err_mm: 628 return err; 629 } 630 EXPORT_SYMBOL_GPL(vhost_dev_set_owner); 631 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org