tree: https://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux.git tapi head: 328004163c637a4505698baa71e5be0c3ee88d95 commit: fdf93d4de9278aba58f3c3290d52c51a3074c184 [3/30] net: add sysfs attribute to control napi threaded mode config: i386-randconfig-m021-20200820 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; smatch warnings: net/core/net-sysfs.c:581 threaded_store() warn: unsigned 'ret' is never less than zero. # https://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux.git/commit/?id... git remote add kuba-linux https://git.kernel.org/pub/scm/linux/kernel/git/kuba/linux.git git fetch --no-tags kuba-linux tapi git checkout fdf93d4de9278aba58f3c3290d52c51a3074c184 vim +/ret +581 net/core/net-sysfs.c 555 556 static ssize_t threaded_store(struct device *dev, 557 struct device_attribute *attr, 558 const char *buf, size_t len) 559 { 560 struct net_device *netdev = to_net_dev(dev); 561 size_t ret; 562 bool val; 563 564 if (!capable(CAP_NET_ADMIN)) 565 return -EPERM; 566 567 if (!rtnl_trylock()) 568 return restart_syscall(); 569 570 if (!dev_isalive(netdev)) { 571 ret = len; 572 goto unlock; 573 } 574 575 if (netdev->flags & IFF_UP) { 576 ret = -EBUSY; 577 goto unlock; 578 } 579 580 ret = kstrtobool(buf, &val); 582 goto unlock; 583 netdev->napi_threaded = val; 584 ret = len; 585 586 unlock: 587 rtnl_unlock(); 588 return ret; 589 } 590 static DEVICE_ATTR_RW(threaded); 591 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org