CC: linux-kernel(a)vger.kernel.org TO: Madhuparna Bhowmik <madhuparnabhowmik10(a)gmail.com&gt; CC: "Paul E. McKenney" <paulmck(a)kernel.org&gt; CC: Amol Grover <frextrite(a)gmail.com&gt; tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2020.05.09a head: f947b264331dde395e790628cf7c41f632cad098 commit: d13fee049fa8e94649aa9914fd1ab5d07da51da4 [57/66] Default enable RCU list lockdep debugging with PROVE_RCU config: powerpc-randconfig-r015-20200515 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 13d44b2a0c7ef404b13b16644765977cd5310fe2) reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu git checkout d13fee049fa8e94649aa9914fd1ab5d07da51da4 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): static int fl_classify(struct sk_buff *skb, const struct tcf_proto *tp, ^ 1 warning generated. vim +/fl_classify +298 net/sched/cls_flower.c e0ace68af2acfe Paul Blakey 2019-07-09 297 77b9900ef53ae0 Jiri Pirko 2015-05-12 @298 static int fl_classify(struct sk_buff *skb, const struct tcf_proto *tp, 77b9900ef53ae0 Jiri Pirko 2015-05-12 299 struct tcf_result *res) 77b9900ef53ae0 Jiri Pirko 2015-05-12 300 { 77b9900ef53ae0 Jiri Pirko 2015-05-12 301 struct cls_fl_head *head = rcu_dereference_bh(tp->root); 77b9900ef53ae0 Jiri Pirko 2015-05-12 302 struct fl_flow_key skb_mkey; e0ace68af2acfe Paul Blakey 2019-07-09 303 struct fl_flow_key skb_key; e0ace68af2acfe Paul Blakey 2019-07-09 304 struct fl_flow_mask *mask; e0ace68af2acfe Paul Blakey 2019-07-09 305 struct cls_fl_filter *f; 77b9900ef53ae0 Jiri Pirko 2015-05-12 306 05cd271fd61a0b Paul Blakey 2018-04-30 307 list_for_each_entry_rcu(mask, &head->masks, list) { 8a9093c79863b5 Jason Baron 2020-02-17 308 flow_dissector_init_keys(&skb_key.control, &skb_key.basic); 05cd271fd61a0b Paul Blakey 2018-04-30 309 fl_clear_masked_range(&skb_key, mask); bc3103f1ed405d Amir Vadai 2016-09-08 310 8212ed777f40c7 Jiri Pirko 2019-06-19 311 skb_flow_dissect_meta(skb, &mask->dissector, &skb_key); 05cd271fd61a0b Paul Blakey 2018-04-30 312 /* skb_flow_dissect() does not set n_proto in case an unknown 05cd271fd61a0b Paul Blakey 2018-04-30 313 * protocol, so do it rather here. 77b9900ef53ae0 Jiri Pirko 2015-05-12 314 */ 77b9900ef53ae0 Jiri Pirko 2015-05-12 315 skb_key.basic.n_proto = skb->protocol; 05cd271fd61a0b Paul Blakey 2018-04-30 316 skb_flow_dissect_tunnel_info(skb, &mask->dissector, &skb_key); e0ace68af2acfe Paul Blakey 2019-07-09 317 skb_flow_dissect_ct(skb, &mask->dissector, &skb_key, e0ace68af2acfe Paul Blakey 2019-07-09 318 fl_ct_info_to_flower_map, e0ace68af2acfe Paul Blakey 2019-07-09 319 ARRAY_SIZE(fl_ct_info_to_flower_map)); 05cd271fd61a0b Paul Blakey 2018-04-30 320 skb_flow_dissect(skb, &mask->dissector, &skb_key, 0); 77b9900ef53ae0 Jiri Pirko 2015-05-12 321 05cd271fd61a0b Paul Blakey 2018-04-30 322 fl_set_masked_key(&skb_mkey, &skb_key, mask); 77b9900ef53ae0 Jiri Pirko 2015-05-12 323 5c72299fba9df4 Amritha Nambiar 2018-11-12 324 f = fl_lookup(mask, &skb_mkey, &skb_key); e8eb36cd8ca93f Amir Vadai 2016-06-13 325 if (f && !tc_skip_sw(f->flags)) { 77b9900ef53ae0 Jiri Pirko 2015-05-12 326 *res = f->res; 77b9900ef53ae0 Jiri Pirko 2015-05-12 327 return tcf_exts_exec(skb, &f->exts, res); 77b9900ef53ae0 Jiri Pirko 2015-05-12 328 } 05cd271fd61a0b Paul Blakey 2018-04-30 329 } 77b9900ef53ae0 Jiri Pirko 2015-05-12 330 return -1; 77b9900ef53ae0 Jiri Pirko 2015-05-12 331 } 77b9900ef53ae0 Jiri Pirko 2015-05-12 332 :::::: The code at line 298 was first introduced by commit :::::: 77b9900ef53ae047e36a37d13a2aa33bb2d60641 tc: introduce Flower classifier :::::: TO: Jiri Pirko <jiri(a)resnulli.us&gt; :::::: CC: David S. Miller <davem(a)davemloft.net&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org