Hi Song, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on bpf-next/master] [also build test WARNING on next-20210817] [cannot apply to bpf/master tip/perf/core v5.14-rc6] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Song-Liu/bpf-lbr-enable-reading-... base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: hexagon-randconfig-r014-20210816 (attached as .config) compiler: clang version 12.0.0 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/bdd132049280755216aa3d2f4417bb425... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Song-Liu/bpf-lbr-enable-reading-LBR-from-tracing-bpf-programs/20210818-093217 git checkout bdd132049280755216aa3d2f4417bb4253b777d1 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon 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 >>): net/bpf/test_run.c:169:14: warning: no previous prototype for function 'bpf_fentry_test1' [-Wmissing-prototypes] int noinline bpf_fentry_test1(int a) ^ net/bpf/test_run.c:169:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test1(int a) ^ static net/bpf/test_run.c:174:14: warning: no previous prototype for function 'bpf_fentry_test2' [-Wmissing-prototypes] int noinline bpf_fentry_test2(int a, u64 b) ^ net/bpf/test_run.c:174:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test2(int a, u64 b) ^ static net/bpf/test_run.c:179:14: warning: no previous prototype for function 'bpf_fentry_test3' [-Wmissing-prototypes] int noinline bpf_fentry_test3(char a, int b, u64 c) ^ net/bpf/test_run.c:179:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test3(char a, int b, u64 c) ^ static net/bpf/test_run.c:184:14: warning: no previous prototype for function 'bpf_fentry_test4' [-Wmissing-prototypes] int noinline bpf_fentry_test4(void *a, char b, int c, u64 d) ^ net/bpf/test_run.c:184:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test4(void *a, char b, int c, u64 d) ^ static net/bpf/test_run.c:189:14: warning: no previous prototype for function 'bpf_fentry_test5' [-Wmissing-prototypes] int noinline bpf_fentry_test5(u64 a, void *b, short c, int d, u64 e) ^ net/bpf/test_run.c:189:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test5(u64 a, void *b, short c, int d, u64 e) ^ static net/bpf/test_run.c:194:14: warning: no previous prototype for function 'bpf_fentry_test6' [-Wmissing-prototypes] int noinline bpf_fentry_test6(u64 a, void *b, short c, int d, void *e, u64 f) ^ net/bpf/test_run.c:194:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test6(u64 a, void *b, short c, int d, void *e, u64 f) ^ static net/bpf/test_run.c:203:14: warning: no previous prototype for function 'bpf_fentry_test7' [-Wmissing-prototypes] int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg) ^ net/bpf/test_run.c:203:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg) ^ static net/bpf/test_run.c:208:14: warning: no previous prototype for function 'bpf_fentry_test8' [-Wmissing-prototypes] int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg) ^ net/bpf/test_run.c:208:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fentry_test8(struct bpf_fentry_test_t *arg) ^ static net/bpf/test_run.c:213:14: warning: no previous prototype for function 'bpf_modify_return_test' [-Wmissing-prototypes] int noinline bpf_modify_return_test(int a, int *b) ^ net/bpf/test_run.c:213:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_modify_return_test(int a, int *b) ^ static net/bpf/test_run.c:219:14: warning: no previous prototype for function 'bpf_kfunc_call_test1' [-Wmissing-prototypes] u64 noinline bpf_kfunc_call_test1(struct sock *sk, u32 a, u64 b, u32 c, u64 d) ^ net/bpf/test_run.c:219:1: note: declare 'static' if the function is not intended to be used outside of this translation unit u64 noinline bpf_kfunc_call_test1(struct sock *sk, u32 a, u64 b, u32 c, u64 d) ^ static net/bpf/test_run.c:224:14: warning: no previous prototype for function 'bpf_kfunc_call_test2' [-Wmissing-prototypes] int noinline bpf_kfunc_call_test2(struct sock *sk, u32 a, u32 b) ^ net/bpf/test_run.c:224:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_kfunc_call_test2(struct sock *sk, u32 a, u32 b) ^ static net/bpf/test_run.c:229:24: warning: no previous prototype for function 'bpf_kfunc_call_test3' [-Wmissing-prototypes] struct sock * noinline bpf_kfunc_call_test3(struct sock *sk) ^ net/bpf/test_run.c:229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct sock * noinline bpf_kfunc_call_test3(struct sock *sk) ^ static int noinline bpf_fexit_loop_test1(int n) ^ net/bpf/test_run.c:234:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int noinline bpf_fexit_loop_test1(int n) ^ static 13 warnings generated. vim +/bpf_fexit_loop_test1 +234 net/bpf/test_run.c 228 230 { 231 return sk; 232 } 233 235 { 236 int i, sum = 0; 237 238 /* the primary goal of this test is to test LBR. Create a lot of 239 * branches in the function, so we can catch it easily. 240 */ 241 for (i = 0; i < n; i++) 242 sum += i; 243 return sum; 244 } 245 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org