tree: https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git ptr head: c49309ef3e137c753d1a87de044f007655fb9958 commit: c49309ef3e137c753d1a87de044f007655fb9958 [1/1] bpf: kptr config: hexagon-randconfig-r001-20220216 (https://download.01.org/0day-ci/archive/20220216/202202161630.kf6vptKz-lk...) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 0e628a783b935c70c80815db6c061ec84f884af5) 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://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git/commit/?id=c4... git remote add ast-bpf https://git.kernel.org/pub/scm/linux/kernel/git/ast/bpf.git git fetch --no-tags ast-bpf ptr git checkout c49309ef3e137c753d1a87de044f007655fb9958 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/bpf/ 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 >>): static const struct bpf_func_proto bpf_kptr_get_proto = { ^ static const struct bpf_func_proto bpf_kptr_xchg_proto = { ^ static const struct bpf_func_proto bpf_kptr_try_set_proto = { ^ 3 warnings generated. vim +/bpf_kptr_get_proto +1395 kernel/bpf/helpers.c 1394 1396 .func = bpf_kptr_get, 1397 .gpl_only = false, 1398 .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, 1399 .arg1_type = ARG_PTR_TO_MAP_VALUE, 1400 }; 1401 1402 BPF_CALL_2(bpf_kptr_xchg, void **, kptr, void *, ptr) 1403 { 1404 /* ptr is ptr_to_btf_id returned from bpf_*_lookup() with ptr->refcnt >= 1 1405 * or ptr == NULL. 1406 * returns ptr_to_btf_id with refcnt >= 1 or NULL 1407 */ 1408 return (long) xchg(kptr, ptr); 1409 } 1410 1412 .func = bpf_kptr_xchg, 1413 .gpl_only = false, 1414 .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, 1415 .arg1_type = ARG_PTR_TO_MAP_VALUE, 1416 }; 1417 1418 BPF_CALL_3(bpf_kptr_try_set, void **, kptr, void *, ptr, int, refcnt_off) 1419 { 1420 /* ptr is ptr_to_btf_id returned from bpf_*_lookup() with ptr->refcnt >= 1 1421 * refcount_inc() has to be done before cmpxchg() because 1422 * another cpu might do bpf_kptr_xchg+release. 1423 */ 1424 refcount_inc((refcount_t *)(ptr + refcnt_off)); 1425 if (cmpxchg(kptr, NULL, ptr)) { 1426 /* refcnt >= 2 here */ 1427 refcount_dec((refcount_t *)(ptr + refcnt_off)); 1428 return -EBUSY; 1429 } 1430 return 0; 1431 } 1432 1434 .func = bpf_kptr_try_set, 1435 .gpl_only = false, 1436 .ret_type = RET_INTEGER, 1437 .arg1_type = ARG_PTR_TO_MAP_VALUE, 1438 .arg2_type = ARG_PTR_TO_BTF_ID, 1439 }; 1440 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org