tree: https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/batch head: 5f1f613266bf58f8424a93e1f8b99c4ac8fa6c2b commit: c04eb2ad90ed0981f4dc7d04249a9c84726f9ef0 [13/29] bpf: Add bpf_tramp_attach layer for trampoline attachment config: um-i386_defconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git/commit/?id... git remote add jolsa-perf https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git git fetch --no-tags jolsa-perf bpf/batch git checkout c04eb2ad90ed0981f4dc7d04249a9c84726f9ef0 # save the attached .config to linux build tree make W=1 ARCH=um SUBARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): kernel/bpf/core.c:1368:12: warning: no previous prototype for 'bpf_probe_read_kernel' [-Wmissing-prototypes] 1368 | u64 __weak bpf_probe_read_kernel(void *dst, u32 size, const void *unsafe_ptr) | ^~~~~~~~~~~~~~~~~~~~~ kernel/bpf/core.c:1811:6: warning: no previous prototype for 'bpf_patch_call_args' [-Wmissing-prototypes] 1811 | void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) | ^~~~~~~~~~~~~~~~~~~ kernel/bpf/core.c: In function 'bpf_prog_free_deferred': 2287 | bpf_tramp_detach(aux->dst_attach); | ^~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/bpf_tramp_detach +2287 kernel/bpf/core.c 2268 2269 static void bpf_prog_free_deferred(struct work_struct *work) 2270 { 2271 struct bpf_prog_aux *aux; 2272 int i; 2273 2274 aux = container_of(work, struct bpf_prog_aux, work); 2275 #ifdef CONFIG_BPF_SYSCALL 2276 bpf_free_kfunc_btf_tab(aux->kfunc_btf_tab); 2277 #endif 2278 bpf_free_used_maps(aux); 2279 bpf_free_used_btfs(aux); 2280 if (bpf_prog_is_dev_bound(aux)) 2281 bpf_prog_offload_destroy(aux->prog); 2282 #ifdef CONFIG_PERF_EVENTS 2283 if (aux->prog->has_callchain_buf) 2284 put_callchain_buffers(); 2285 #endif 2286 if (aux->dst_attach) 2288 for (i = 0; i < aux->func_cnt; i++) { 2289 /* We can just unlink the subprog poke descriptor table as 2290 * it was originally linked to the main program and is also 2291 * released along with it. 2292 */ 2293 aux->func[i]->aux->poke_tab = NULL; 2294 bpf_jit_free(aux->func[i]); 2295 } 2296 if (aux->func_cnt) { 2297 kfree(aux->func); 2298 bpf_prog_unlock_free(aux->prog); 2299 } else { 2300 bpf_jit_free(aux->prog); 2301 } 2302 } 2303 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org