Hi Alexei, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on bpf-next/master] url: https://github.com/0day-ci/linux/commits/Alexei-Starovoitov/bpf-Introduce... base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: m68k-randconfig-r012-20210522 (attached as .config) compiler: m68k-linux-gcc (GCC) 9.3.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/9380db20bb780c2f5147a795ac7f5fc13... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Alexei-Starovoitov/bpf-Introduce-bpf_timer/20210522-204413 git checkout 9380db20bb780c2f5147a795ac7f5fc133f66d55 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=m68k If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): kernel/bpf/helpers.c: In function 'timer_cb': kernel/bpf/helpers.c:1000:18: warning: unused variable 'map' [-Wunused-variable] 1000 | struct bpf_map *map; | ^~~ kernel/bpf/helpers.c: In function '____bpf_timer_mod': 1043 | tl = (struct bpf_timer_list *)timer->opaque; | ^ kernel/bpf/helpers.c: In function '____bpf_timer_del': kernel/bpf/helpers.c:1068:7: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] 1068 | tl = (struct bpf_timer_list *)timer->opaque; | ^ vim +1043 kernel/bpf/helpers.c 1038 1039 BPF_CALL_2(bpf_timer_mod, struct bpf_timer *, timer, u64, msecs) 1040 { 1041 struct bpf_timer_list *tl; 1042 1044 if (!tl) 1045 return -EINVAL; 1046 /* keep the prog alive until callback is invoked */ 1047 if (!mod_timer(&tl->tl, jiffies + msecs_to_jiffies(msecs))) { 1048 /* The timer was inactive. 1049 * Keep the prog alive until callback is invoked 1050 */ 1051 bpf_prog_inc(tl->prog); 1052 } 1053 return 0; 1054 } 1055 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org