Hi Lorenzo, I love your patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Lorenzo-Bianconi/netdev-genl-create-a-simple-family-for-netdev-stuff/20230121-011957 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/272fa19f57de2d14e9666b4cd9b1ae8a61a94807.1674234430.git.lorenzo%40kernel.org patch subject: [PATCH bpf-next 1/7] netdev-genl: create a simple family for netdev stuff config: x86_64-rhel-8.3-syz (https://download.01.org/0day-ci/archive/20230121/202301211259.eI8T3TMB-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-8) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/bab8ed890888146e07283e2ae27174b3562b6931 git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Lorenzo-Bianconi/netdev-genl-create-a-simple-family-for-netdev-stuff/20230121-011957 git checkout bab8ed890888146e07283e2ae27174b3562b6931 # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=x86_64 olddefconfig make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash net/core/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): net/core/netdev-genl.c: In function 'netdev_nl_dev_fill': >> net/core/netdev-genl.c:16:13: warning: unused variable 'err' [-Wunused-variable] 16 | int err; | ^~~ vim +/err +16 net/core/netdev-genl.c 10 11 static int 12 netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp, 13 u32 portid, u32 seq, int flags, u32 cmd) 14 { 15 void *hdr; > 16 int err; 17 18 hdr = genlmsg_put(rsp, portid, seq, &netdev_nl_family, flags, cmd); 19 if (!hdr) 20 return -EMSGSIZE; 21 22 if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) || 23 nla_put_u64_64bit(rsp, NETDEV_A_DEV_XDP_FEATURES, 24 netdev->xdp_features, NETDEV_A_DEV_PAD)) { 25 genlmsg_cancel(rsp, hdr); 26 return -EINVAL; 27 } 28 29 genlmsg_end(rsp, hdr); 30 31 return 0; 32 } 33 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests