Hi Blaise, kernel test robot noticed the following build errors: [auto build test ERROR on bpf/master] [also build test ERROR on linus/master v6.13-rc6] [cannot apply to bpf-next/master next-20250110] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Blaise-Boscaccy/bpf-Add-data-structures-for-managing-in-kernel-eBPF-relocations/20250110-064354 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git master patch link: https://lore.kernel.org/r/20250109214617.485144-10-bboscaccy%40linux.microsoft.com patch subject: [PATCH 09/14] bpf: Collect extern relocations config: i386-buildonly-randconfig-006-20250111 (https://download.01.org/0day-ci/archive/20250111/202501110801.7aGt26Oh-lkp@xxxxxxxxx/config) compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250111/202501110801.7aGt26Oh-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202501110801.7aGt26Oh-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): >> kernel/bpf/syscall.c:6438:22: error: incompatible pointer types passing 'Elf32_Sym *' (aka 'struct elf32_sym *') to parameter of type 'const Elf64_Sym *' (aka 'const struct elf64_sym *') [-Werror,-Wincompatible-pointer-types] 6438 | if (!sym_is_extern(&sym[i])) | ^~~~~~~ kernel/bpf/syscall.c:6082:44: note: passing argument to parameter 'sym' here 6082 | static bool sym_is_extern(const Elf64_Sym *sym) | ^ kernel/bpf/syscall.c:6463:20: error: call to undeclared function 'bpf_core_essential_name_len'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 6463 | ext_essent_len = bpf_core_essential_name_len(ext->name); | ^ kernel/bpf/syscall.c:7097:30: warning: bitwise operation between different enumeration types ('enum bpf_arg_type' and 'enum bpf_type_flag') [-Wenum-enum-conversion] 7097 | .arg2_type = ARG_PTR_TO_MEM | MEM_RDONLY, | ~~~~~~~~~~~~~~ ^ ~~~~~~~~~~ kernel/bpf/syscall.c:7147:41: warning: bitwise operation between different enumeration types ('enum bpf_arg_type' and 'enum bpf_type_flag') [-Wenum-enum-conversion] 7147 | .arg4_type = ARG_PTR_TO_FIXED_SIZE_MEM | MEM_UNINIT | MEM_WRITE | MEM_ALIGNED, | ~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~ 2 warnings and 2 errors generated. vim +6438 kernel/bpf/syscall.c 6412 6413 static int collect_externs(struct bpf_obj *obj) 6414 { 6415 int i, n, off, dummy_var_btf_id; 6416 Elf_Shdr *symsec = &obj->sechdrs[obj->index.sym]; 6417 Elf_Sym *sym = (void *)obj->hdr + symsec->sh_offset; 6418 const char *ext_name; 6419 const char *sec_name; 6420 struct bpf_extern_desc *ext; 6421 const struct btf_type *t; 6422 size_t ext_essent_len; 6423 struct btf_type *sec, *kcfg_sec = NULL, *ksym_sec = NULL; 6424 int size; 6425 int int_btf_id; 6426 const struct btf_type *dummy_var; 6427 struct btf_type *vt; 6428 struct btf_var_secinfo *vs; 6429 const struct btf_type *func_proto; 6430 struct btf_param *param; 6431 int j; 6432 6433 dummy_var_btf_id = add_dummy_ksym_var(obj->btf); 6434 if (dummy_var_btf_id < 0) 6435 return dummy_var_btf_id; 6436 6437 for (i = 1; i < symsec->sh_size / sizeof(Elf_Sym); i++) { > 6438 if (!sym_is_extern(&sym[i])) 6439 continue; 6440 6441 ext_name = obj->strtab + sym[i].st_name; 6442 ext = krealloc_array(obj->externs, 6443 obj->nr_extern + 1, 6444 sizeof(struct bpf_extern_desc), 6445 GFP_KERNEL); 6446 if (!ext) 6447 return -ENOMEM; 6448 6449 obj->externs = ext; 6450 ext = &ext[obj->nr_extern]; 6451 memset(ext, 0, sizeof(*ext)); 6452 obj->nr_extern++; 6453 6454 ext->btf_id = find_extern_btf_id(obj->btf, ext_name); 6455 if (ext->btf_id <= 0) 6456 return ext->btf_id; 6457 6458 t = btf_type_by_id(obj->btf, ext->btf_id); 6459 ext->name = btf_str_by_offset(obj->btf, t->name_off); 6460 ext->sym_idx = i; 6461 ext->is_weak = ELF64_ST_BIND(sym->st_info) == STB_WEAK; 6462 6463 ext_essent_len = bpf_core_essential_name_len(ext->name); 6464 ext->essent_name = NULL; 6465 if (ext_essent_len != strlen(ext->name)) { 6466 ext->essent_name = kstrndup(ext->name, ext_essent_len, GFP_KERNEL); 6467 if (!ext->essent_name) 6468 return -ENOMEM; 6469 } 6470 6471 ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id); 6472 if (ext->sec_btf_id <= 0) { 6473 pr_warn("failed to find BTF for extern '%s' [%d] section: %d\n", 6474 ext_name, ext->btf_id, ext->sec_btf_id); 6475 return ext->sec_btf_id; 6476 } 6477 6478 sec = (void *)btf_type_by_id(obj->btf, ext->sec_btf_id); 6479 sec_name = btf_str_by_offset(obj->btf, sec->name_off); 6480 6481 if (strcmp(sec_name, ".kconfig") == 0) { 6482 if (btf_type_is_func(t)) { 6483 pr_warn("extern function %s is unsupported under .kconfig section\n", 6484 ext->name); 6485 return -EOPNOTSUPP; 6486 } 6487 kcfg_sec = sec; 6488 ext->type = EXT_KCFG; 6489 6490 if (!btf_resolve_size(obj->btf, t, &size)) { 6491 pr_warn("failed to resolve size of extern (kcfg) '%s': %d\n", 6492 ext_name, ext->kcfg.sz); 6493 return -EINVAL; 6494 } 6495 ext->kcfg.sz = size; 6496 ext->kcfg.align = btf_align_of(obj->btf, t->type); 6497 if (ext->kcfg.align <= 0) { 6498 pr_warn("failed to determine alignment of extern (kcfg) '%s': %d\n", 6499 ext_name, ext->kcfg.align); 6500 return -EINVAL; 6501 } 6502 ext->kcfg.type = find_kcfg_type(obj->btf, t->type, 6503 &ext->kcfg.is_signed); 6504 if (ext->kcfg.type == KCFG_UNKNOWN) { 6505 pr_warn("extern (kcfg) '%s': type is unsupported\n", ext_name); 6506 return -EOPNOTSUPP; 6507 } 6508 } else if (strcmp(sec_name, ".ksyms") == 0) { 6509 ksym_sec = sec; 6510 ext->type = EXT_KSYM; 6511 skip_mods_and_typedefs(obj->btf, t->type, 6512 &ext->ksym.type_id); 6513 } else { 6514 pr_warn("unrecognized extern section '%s'\n", sec_name); 6515 return -EOPNOTSUPP; 6516 } 6517 } 6518 6519 sort(obj->externs, obj->nr_extern, sizeof(struct bpf_extern_desc), 6520 cmp_externs, NULL); 6521 6522 if (ksym_sec) { 6523 /* find existing 4-byte integer type in BTF to use for fake 6524 * extern variables in DATASEC 6525 */ 6526 int_btf_id = find_int_btf_id(obj->btf); 6527 6528 /* For extern function, a dummy_var added earlier 6529 * will be used to replace the vs->type and 6530 * its name string will be used to refill 6531 * the missing param's name. 6532 */ 6533 dummy_var = btf_type_by_id(obj->btf, dummy_var_btf_id); 6534 for (i = 0; i < obj->nr_extern; i++) { 6535 ext = &obj->externs[i]; 6536 if (ext->type != EXT_KSYM) 6537 continue; 6538 pr_debug("extern (ksym) #%d: symbol %d, name %s\n", 6539 i, ext->sym_idx, ext->name); 6540 } 6541 6542 sec = ksym_sec; 6543 n = btf_vlen(sec); 6544 for (i = 0, off = 0; i < n; i++, off += sizeof(int)) { 6545 vs = btf_var_secinfos(sec) + i; 6546 vt = (void *)btf_type_by_id(obj->btf, vs->type); 6547 ext_name = btf_str_by_offset(obj->btf, vt->name_off); 6548 ext = find_extern_by_name(obj, ext_name); 6549 if (!ext) { 6550 pr_warn("failed to find extern definition for BTF %s\n", 6551 ext_name); 6552 return -ESRCH; 6553 } 6554 if (btf_type_is_func(vt)) { 6555 func_proto = btf_type_by_id(obj->btf, 6556 vt->type); 6557 param = btf_params(func_proto); 6558 /* Reuse the dummy_var string if the 6559 * func proto does not have param name. 6560 */ 6561 for (j = 0; j < btf_vlen(func_proto); j++) 6562 if (param[j].type && !param[j].name_off) 6563 param[j].name_off = 6564 dummy_var->name_off; 6565 vs->type = dummy_var_btf_id; 6566 vt->info &= ~0xffff; 6567 vt->info |= BTF_FUNC_GLOBAL; 6568 } else { 6569 btf_var(vt)->linkage = BTF_VAR_GLOBAL_ALLOCATED; 6570 vt->type = int_btf_id; 6571 } 6572 vs->offset = off; 6573 vs->size = sizeof(int); 6574 } 6575 sec->size = off; 6576 } 6577 6578 if (kcfg_sec) { 6579 sec = kcfg_sec; 6580 /* for kcfg externs calculate their offsets within a .kconfig map */ 6581 off = 0; 6582 for (i = 0; i < obj->nr_extern; i++) { 6583 ext = &obj->externs[i]; 6584 if (ext->type != EXT_KCFG) 6585 continue; 6586 6587 ext->kcfg.data_off = roundup(off, ext->kcfg.align); 6588 off = ext->kcfg.data_off + ext->kcfg.sz; 6589 pr_debug("extern (kcfg) #%d: symbol %d, off %u, name %s\n", 6590 i, ext->sym_idx, ext->kcfg.data_off, ext->name); 6591 } 6592 sec->size = off; 6593 n = btf_vlen(sec); 6594 for (i = 0; i < n; i++) { 6595 vs = btf_var_secinfos(sec) + i; 6596 t = btf_type_by_id(obj->btf, vs->type); 6597 ext_name = btf_str_by_offset(obj->btf, t->name_off); 6598 6599 ext = find_extern_by_name(obj, ext_name); 6600 if (!ext) { 6601 pr_warn("failed to find extern definition for BTF var '%s'\n", 6602 ext_name); 6603 return -ESRCH; 6604 } 6605 btf_var(t)->linkage = BTF_VAR_GLOBAL_ALLOCATED; 6606 vs->offset = ext->kcfg.data_off; 6607 } 6608 } 6609 return 0; 6610 } 6611 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
