Hi Arthur, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on net-next/master] [also build test WARNING on next-20191112] [cannot apply to v5.4-rc7] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Arthur-Fabre/sfc-trace_xdp_excep... base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git ca22d6977b9b4ab0fd2e7909b57e32ba5b95046f config: mips-allmodconfig (attached as .config) compiler: mips-linux-gcc (GCC) 7.4.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree GCC_VERSION=7.4.0 make.cross ARCH=mips If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): In file included from include/trace/events/xdp.h:10:0, from include/linux/bpf_trace.h:5, from drivers/net/ethernet/sfc/rx.c:21: drivers/net/ethernet/sfc/rx.c: In function '__efx_rx_packet': ((void(*)(proto))(it_func))(args); \ ^ drivers/net/ethernet/sfc/rx.c:658:6: note: 'xdp_act' was declared here u32 xdp_act; ^~~~~~~ -- In file included from include/trace/events/xdp.h:10:0, from include/linux/bpf_trace.h:5, from drivers/net//ethernet/sfc/rx.c:21: drivers/net//ethernet/sfc/rx.c: In function '__efx_rx_packet': ((void(*)(proto))(it_func))(args); \ ^ drivers/net//ethernet/sfc/rx.c:658:6: note: 'xdp_act' was declared here u32 xdp_act; ^~~~~~~ vim +/xdp_act +193 include/linux/tracepoint.h 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 151 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 152 /* 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 153 * it_func[0] is never NULL because there is at least one element in the array 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 154 * when the array itself is non NULL. 38516ab59fbc5b Steven Rostedt 2010-04-20 155 * 38516ab59fbc5b Steven Rostedt 2010-04-20 156 * Note, the proto and args passed in includes "__data" as the first parameter. 38516ab59fbc5b Steven Rostedt 2010-04-20 157 * The reason for this is to handle the "void" prototype. If a tracepoint 38516ab59fbc5b Steven Rostedt 2010-04-20 158 * has a "void" prototype, then it is invalid to declare a function 38516ab59fbc5b Steven Rostedt 2010-04-20 159 * as "(void *, void)". The DECLARE_TRACE_NOARGS() will pass in just 38516ab59fbc5b Steven Rostedt 2010-04-20 160 * "void *data", where as the DECLARE_TRACE() will pass in "void *data, proto". 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 161 */ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 162) #define __DO_TRACE(tp, proto, args, cond, rcuidle) \ 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 163 do { \ 38516ab59fbc5b Steven Rostedt 2010-04-20 164 struct tracepoint_func *it_func_ptr; \ 38516ab59fbc5b Steven Rostedt 2010-04-20 165 void *it_func; \ 38516ab59fbc5b Steven Rostedt 2010-04-20 166 void *__data; \ 0c7a52e4d4b5c4 Zenghui Yu 2018-11-28 167 int __maybe_unused __idx = 0; \ 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 168 \ 287050d3902644 Steven Rostedt 2010-12-02 169 if (!(cond)) \ 287050d3902644 Steven Rostedt 2010-12-02 170 return; \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 171) \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 172) /* srcu can't be used from NMI */ \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 173) WARN_ON_ONCE(rcuidle && in_nmi()); \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 174) \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 175) /* keep srcu and sched-rcu usage consistent */ \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 176) preempt_disable_notrace(); \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 177) \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 178) /* \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 179) * For rcuidle callers, use srcu since sched-rcu \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 180) * doesn't work from the idle path. \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 181) */ \ 865e63b04e9b2a Steven Rostedt (VMware 2018-09-04 182) if (rcuidle) { \ 0c7a52e4d4b5c4 Zenghui Yu 2018-11-28 183 __idx = srcu_read_lock_notrace(&tracepoint_srcu);\ 865e63b04e9b2a Steven Rostedt (VMware 2018-09-04 184) rcu_irq_enter_irqson(); \ 865e63b04e9b2a Steven Rostedt (VMware 2018-09-04 185) } \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 186) \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 187) it_func_ptr = rcu_dereference_raw((tp)->funcs); \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 188) \ 38516ab59fbc5b Steven Rostedt 2010-04-20 189 if (it_func_ptr) { \ 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 190 do { \ 38516ab59fbc5b Steven Rostedt 2010-04-20 191 it_func = (it_func_ptr)->func; \ 38516ab59fbc5b Steven Rostedt 2010-04-20 192 __data = (it_func_ptr)->data; \ 38516ab59fbc5b Steven Rostedt 2010-04-20 @193 ((void(*)(proto))(it_func))(args); \ 38516ab59fbc5b Steven Rostedt 2010-04-20 194 } while ((++it_func_ptr)->func); \ 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 195 } \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 196) \ 865e63b04e9b2a Steven Rostedt (VMware 2018-09-04 197) if (rcuidle) { \ 865e63b04e9b2a Steven Rostedt (VMware 2018-09-04 198) rcu_irq_exit_irqson(); \ 0c7a52e4d4b5c4 Zenghui Yu 2018-11-28 199 srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\ 865e63b04e9b2a Steven Rostedt (VMware 2018-09-04 200) } \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 201) \ e6753f23d961d6 Joel Fernandes (Google 2018-07-30 202) preempt_enable_notrace(); \ 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 203 } while (0) 97e1c18e8d17bd Mathieu Desnoyers 2008-07-18 204 :::::: The code at line 193 was first introduced by commit :::::: 38516ab59fbc5b3bb278cf5e1fe2867c70cff32e tracing: Let tracepoints have data passed to tracepoint callbacks :::::: TO: Steven Rostedt <srostedt(a)redhat.com&gt; :::::: CC: Steven Rostedt <rostedt(a)goodmis.org&gt; --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org Intel Corporation