CC: [email protected] In-Reply-To: <[email protected]> References: <[email protected]> TO: Dmitrii Banshchikov <[email protected]> TO: [email protected] CC: Dmitrii Banshchikov <[email protected]> CC: [email protected] CC: [email protected] CC: [email protected] CC: [email protected] CC: [email protected] CC: [email protected] CC: [email protected] CC: [email protected]
Hi Dmitrii, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/0day-ci/linux/commits/Dmitrii-Banshchikov/bpf-use-MAX_BPF_FUNC_REGISTER_ARGS-macro/20210222-173228 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master :::::: branch date: 4 hours ago :::::: commit date: 4 hours ago compiler: nds32le-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <[email protected]> cppcheck possible warnings: (new ones prefixed by >>, may not real problems) kernel/bpf/btf.c:5723:13: warning: Boolean result is used in bitwise operation. Clarify expression with parentheses. [clarifyCondition] if (!uname ^ !uname_len) ^ >> kernel/bpf/btf.c:4596:38: warning: Either the condition >> 't?btf_type_vlen(t):MAX_BPF_FUNC_REGISTER_ARGS' is redundant or there is >> pointer arithmetic with NULL pointer. [nullPointerArithmeticRedundantCheck] args = (const struct btf_param *)(t + 1); ^ kernel/bpf/btf.c:4600:14: note: Assuming that condition 't?btf_type_vlen(t):MAX_BPF_FUNC_REGISTER_ARGS' is not redundant nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REGISTER_ARGS; ^ kernel/bpf/btf.c:4596:38: note: Null pointer addition args = (const struct btf_param *)(t + 1); ^ vim +4596 kernel/bpf/btf.c 84ad7a7ab69f11 Jiri Olsa 2020-01-23 4576 9e15db66136a14 Alexei Starovoitov 2019-10-15 4577 bool btf_ctx_access(int off, int size, enum bpf_access_type type, 9e15db66136a14 Alexei Starovoitov 2019-10-15 4578 const struct bpf_prog *prog, 9e15db66136a14 Alexei Starovoitov 2019-10-15 4579 struct bpf_insn_access_aux *info) 9e15db66136a14 Alexei Starovoitov 2019-10-15 4580 { 38207291604401 Martin KaFai Lau 2019-10-24 4581 const struct btf_type *t = prog->aux->attach_func_proto; 3aac1ead5eb6b7 Toke Høiland-Jørgensen 2020-09-29 4582 struct bpf_prog *tgt_prog = prog->aux->dst_prog; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4583 struct btf *btf = bpf_prog_get_target_btf(prog); 38207291604401 Martin KaFai Lau 2019-10-24 4584 const char *tname = prog->aux->attach_func_name; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4585 struct bpf_verifier_log *log = info->log; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4586 const struct btf_param *args; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4587 u32 nr_args, arg; 3c32cc1bceba8a Yonghong Song 2020-05-13 4588 int i, ret; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4589 9e15db66136a14 Alexei Starovoitov 2019-10-15 4590 if (off % 8) { 38207291604401 Martin KaFai Lau 2019-10-24 4591 bpf_log(log, "func '%s' offset %d is not multiple of 8\n", 9e15db66136a14 Alexei Starovoitov 2019-10-15 4592 tname, off); 9e15db66136a14 Alexei Starovoitov 2019-10-15 4593 return false; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4594 } 9e15db66136a14 Alexei Starovoitov 2019-10-15 4595 arg = off / 8; 9e15db66136a14 Alexei Starovoitov 2019-10-15 @4596 args = (const struct btf_param *)(t + 1); 1147a89a1feec0 Dmitrii Banshchikov 2021-02-22 4597 /* if (t == NULL) Fall back to default BPF prog with 1147a89a1feec0 Dmitrii Banshchikov 2021-02-22 4598 * MAX_BPF_FUNC_REGISTER_ARGS u64 arguments. 1147a89a1feec0 Dmitrii Banshchikov 2021-02-22 4599 */ 1147a89a1feec0 Dmitrii Banshchikov 2021-02-22 4600 nr_args = t ? btf_type_vlen(t) : MAX_BPF_FUNC_REGISTER_ARGS; 38207291604401 Martin KaFai Lau 2019-10-24 4601 if (prog->aux->attach_btf_trace) { 9e15db66136a14 Alexei Starovoitov 2019-10-15 4602 /* skip first 'void *__data' argument in btf_trace_##name typedef */ 9e15db66136a14 Alexei Starovoitov 2019-10-15 4603 args++; 38207291604401 Martin KaFai Lau 2019-10-24 4604 nr_args--; 38207291604401 Martin KaFai Lau 2019-10-24 4605 } fec56f5890d93f Alexei Starovoitov 2019-11-14 4606 f50b49a0bfcaf5 KP Singh 2020-03-30 4607 if (arg > nr_args) { f50b49a0bfcaf5 KP Singh 2020-03-30 4608 bpf_log(log, "func '%s' doesn't have %d-th argument\n", f50b49a0bfcaf5 KP Singh 2020-03-30 4609 tname, arg + 1); f50b49a0bfcaf5 KP Singh 2020-03-30 4610 return false; f50b49a0bfcaf5 KP Singh 2020-03-30 4611 } f50b49a0bfcaf5 KP Singh 2020-03-30 4612 6ba43b761c4134 KP Singh 2020-03-04 4613 if (arg == nr_args) { f50b49a0bfcaf5 KP Singh 2020-03-30 4614 switch (prog->expected_attach_type) { f50b49a0bfcaf5 KP Singh 2020-03-30 4615 case BPF_LSM_MAC: f50b49a0bfcaf5 KP Singh 2020-03-30 4616 case BPF_TRACE_FEXIT: 9e4e01dfd3254c KP Singh 2020-03-29 4617 /* When LSM programs are attached to void LSM hooks 9e4e01dfd3254c KP Singh 2020-03-29 4618 * they use FEXIT trampolines and when attached to 9e4e01dfd3254c KP Singh 2020-03-29 4619 * int LSM hooks, they use MODIFY_RETURN trampolines. 9e4e01dfd3254c KP Singh 2020-03-29 4620 * 9e4e01dfd3254c KP Singh 2020-03-29 4621 * While the LSM programs are BPF_MODIFY_RETURN-like 9e4e01dfd3254c KP Singh 2020-03-29 4622 * the check: 9e4e01dfd3254c KP Singh 2020-03-29 4623 * 9e4e01dfd3254c KP Singh 2020-03-29 4624 * if (ret_type != 'int') 9e4e01dfd3254c KP Singh 2020-03-29 4625 * return -EINVAL; 9e4e01dfd3254c KP Singh 2020-03-29 4626 * 9e4e01dfd3254c KP Singh 2020-03-29 4627 * is _not_ done here. This is still safe as LSM hooks 9e4e01dfd3254c KP Singh 2020-03-29 4628 * have only void and int return types. 9e4e01dfd3254c KP Singh 2020-03-29 4629 */ 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4630 if (!t) 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4631 return true; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4632 t = btf_type_by_id(btf, t->type); f50b49a0bfcaf5 KP Singh 2020-03-30 4633 break; f50b49a0bfcaf5 KP Singh 2020-03-30 4634 case BPF_MODIFY_RETURN: 6ba43b761c4134 KP Singh 2020-03-04 4635 /* For now the BPF_MODIFY_RETURN can only be attached to 6ba43b761c4134 KP Singh 2020-03-04 4636 * functions that return an int. 6ba43b761c4134 KP Singh 2020-03-04 4637 */ 6ba43b761c4134 KP Singh 2020-03-04 4638 if (!t) 6ba43b761c4134 KP Singh 2020-03-04 4639 return false; 6ba43b761c4134 KP Singh 2020-03-04 4640 6ba43b761c4134 KP Singh 2020-03-04 4641 t = btf_type_skip_modifiers(btf, t->type, NULL); a9b59159d338d4 John Fastabend 2020-06-24 4642 if (!btf_type_is_small_int(t)) { 6ba43b761c4134 KP Singh 2020-03-04 4643 bpf_log(log, 6ba43b761c4134 KP Singh 2020-03-04 4644 "ret type %s not allowed for fmod_ret\n", 6ba43b761c4134 KP Singh 2020-03-04 4645 btf_kind_str[BTF_INFO_KIND(t->info)]); 6ba43b761c4134 KP Singh 2020-03-04 4646 return false; 6ba43b761c4134 KP Singh 2020-03-04 4647 } f50b49a0bfcaf5 KP Singh 2020-03-30 4648 break; f50b49a0bfcaf5 KP Singh 2020-03-30 4649 default: 38207291604401 Martin KaFai Lau 2019-10-24 4650 bpf_log(log, "func '%s' doesn't have %d-th argument\n", fec56f5890d93f Alexei Starovoitov 2019-11-14 4651 tname, arg + 1); 9e15db66136a14 Alexei Starovoitov 2019-10-15 4652 return false; f50b49a0bfcaf5 KP Singh 2020-03-30 4653 } fec56f5890d93f Alexei Starovoitov 2019-11-14 4654 } else { 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4655 if (!t) 1147a89a1feec0 Dmitrii Banshchikov 2021-02-22 4656 /* Default prog with MAX_BPF_FUNC_REGISTER_ARGS args */ 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4657 return true; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4658 t = btf_type_by_id(btf, args[arg].type); fec56f5890d93f Alexei Starovoitov 2019-11-14 4659 } f50b49a0bfcaf5 KP Singh 2020-03-30 4660 9e15db66136a14 Alexei Starovoitov 2019-10-15 4661 /* skip modifiers */ 9e15db66136a14 Alexei Starovoitov 2019-10-15 4662 while (btf_type_is_modifier(t)) 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4663 t = btf_type_by_id(btf, t->type); a9b59159d338d4 John Fastabend 2020-06-24 4664 if (btf_type_is_small_int(t) || btf_type_is_enum(t)) 9e15db66136a14 Alexei Starovoitov 2019-10-15 4665 /* accessing a scalar */ 9e15db66136a14 Alexei Starovoitov 2019-10-15 4666 return true; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4667 if (!btf_type_is_ptr(t)) { 9e15db66136a14 Alexei Starovoitov 2019-10-15 4668 bpf_log(log, 38207291604401 Martin KaFai Lau 2019-10-24 4669 "func '%s' arg%d '%s' has type %s. Only pointer access is allowed\n", 9e15db66136a14 Alexei Starovoitov 2019-10-15 4670 tname, arg, 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4671 __btf_name_by_offset(btf, t->name_off), 9e15db66136a14 Alexei Starovoitov 2019-10-15 4672 btf_kind_str[BTF_INFO_KIND(t->info)]); 9e15db66136a14 Alexei Starovoitov 2019-10-15 4673 return false; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4674 } afbf21dce668ef Yonghong Song 2020-07-23 4675 afbf21dce668ef Yonghong Song 2020-07-23 4676 /* check for PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL */ afbf21dce668ef Yonghong Song 2020-07-23 4677 for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { afbf21dce668ef Yonghong Song 2020-07-23 4678 const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; afbf21dce668ef Yonghong Song 2020-07-23 4679 afbf21dce668ef Yonghong Song 2020-07-23 4680 if (ctx_arg_info->offset == off && afbf21dce668ef Yonghong Song 2020-07-23 4681 (ctx_arg_info->reg_type == PTR_TO_RDONLY_BUF_OR_NULL || afbf21dce668ef Yonghong Song 2020-07-23 4682 ctx_arg_info->reg_type == PTR_TO_RDWR_BUF_OR_NULL)) { afbf21dce668ef Yonghong Song 2020-07-23 4683 info->reg_type = ctx_arg_info->reg_type; afbf21dce668ef Yonghong Song 2020-07-23 4684 return true; afbf21dce668ef Yonghong Song 2020-07-23 4685 } afbf21dce668ef Yonghong Song 2020-07-23 4686 } afbf21dce668ef Yonghong Song 2020-07-23 4687 9e15db66136a14 Alexei Starovoitov 2019-10-15 4688 if (t->type == 0) 9e15db66136a14 Alexei Starovoitov 2019-10-15 4689 /* This is a pointer to void. 9e15db66136a14 Alexei Starovoitov 2019-10-15 4690 * It is the same as scalar from the verifier safety pov. 9e15db66136a14 Alexei Starovoitov 2019-10-15 4691 * No further pointer walking is allowed. 9e15db66136a14 Alexei Starovoitov 2019-10-15 4692 */ 9e15db66136a14 Alexei Starovoitov 2019-10-15 4693 return true; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4694 84ad7a7ab69f11 Jiri Olsa 2020-01-23 4695 if (is_string_ptr(btf, t)) 84ad7a7ab69f11 Jiri Olsa 2020-01-23 4696 return true; 84ad7a7ab69f11 Jiri Olsa 2020-01-23 4697 9e15db66136a14 Alexei Starovoitov 2019-10-15 4698 /* this is a pointer to another type */ 3c32cc1bceba8a Yonghong Song 2020-05-13 4699 for (i = 0; i < prog->aux->ctx_arg_info_size; i++) { 3c32cc1bceba8a Yonghong Song 2020-05-13 4700 const struct bpf_ctx_arg_aux *ctx_arg_info = &prog->aux->ctx_arg_info[i]; 3c32cc1bceba8a Yonghong Song 2020-05-13 4701 3c32cc1bceba8a Yonghong Song 2020-05-13 4702 if (ctx_arg_info->offset == off) { 3c32cc1bceba8a Yonghong Song 2020-05-13 4703 info->reg_type = ctx_arg_info->reg_type; 22dc4a0f5ed11b Andrii Nakryiko 2020-12-03 4704 info->btf = btf_vmlinux; 951cf368bcb11d Yonghong Song 2020-07-20 4705 info->btf_id = ctx_arg_info->btf_id; 951cf368bcb11d Yonghong Song 2020-07-20 4706 return true; 3c32cc1bceba8a Yonghong Song 2020-05-13 4707 } 3c32cc1bceba8a Yonghong Song 2020-05-13 4708 } 9e15db66136a14 Alexei Starovoitov 2019-10-15 4709 951cf368bcb11d Yonghong Song 2020-07-20 4710 info->reg_type = PTR_TO_BTF_ID; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4711 if (tgt_prog) { 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4712 enum bpf_prog_type tgt_type; 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4713 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4714 if (tgt_prog->type == BPF_PROG_TYPE_EXT) 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4715 tgt_type = tgt_prog->aux->saved_dst_prog_type; 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4716 else 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4717 tgt_type = tgt_prog->type; 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4718 43bc2874e779c1 Toke Høiland-Jørgensen 2020-09-29 4719 ret = btf_translate_to_vmlinux(log, btf, t, tgt_type, arg); 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4720 if (ret > 0) { 22dc4a0f5ed11b Andrii Nakryiko 2020-12-03 4721 info->btf = btf_vmlinux; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4722 info->btf_id = ret; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4723 return true; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4724 } else { 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4725 return false; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4726 } 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4727 } 275517ff452a53 Martin KaFai Lau 2020-01-08 4728 22dc4a0f5ed11b Andrii Nakryiko 2020-12-03 4729 info->btf = btf; 275517ff452a53 Martin KaFai Lau 2020-01-08 4730 info->btf_id = t->type; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4731 t = btf_type_by_id(btf, t->type); 9e15db66136a14 Alexei Starovoitov 2019-10-15 4732 /* skip modifiers */ 275517ff452a53 Martin KaFai Lau 2020-01-08 4733 while (btf_type_is_modifier(t)) { 275517ff452a53 Martin KaFai Lau 2020-01-08 4734 info->btf_id = t->type; 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4735 t = btf_type_by_id(btf, t->type); 275517ff452a53 Martin KaFai Lau 2020-01-08 4736 } 9e15db66136a14 Alexei Starovoitov 2019-10-15 4737 if (!btf_type_is_struct(t)) { 9e15db66136a14 Alexei Starovoitov 2019-10-15 4738 bpf_log(log, 38207291604401 Martin KaFai Lau 2019-10-24 4739 "func '%s' arg%d type %s is not a struct\n", 9e15db66136a14 Alexei Starovoitov 2019-10-15 4740 tname, arg, btf_kind_str[BTF_INFO_KIND(t->info)]); 9e15db66136a14 Alexei Starovoitov 2019-10-15 4741 return false; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4742 } 38207291604401 Martin KaFai Lau 2019-10-24 4743 bpf_log(log, "func '%s' arg%d has btf_id %d type %s '%s'\n", 9e15db66136a14 Alexei Starovoitov 2019-10-15 4744 tname, arg, info->btf_id, btf_kind_str[BTF_INFO_KIND(t->info)], 5b92a28aae4dd0 Alexei Starovoitov 2019-11-14 4745 __btf_name_by_offset(btf, t->name_off)); 9e15db66136a14 Alexei Starovoitov 2019-10-15 4746 return true; 9e15db66136a14 Alexei Starovoitov 2019-10-15 4747 } 9e15db66136a14 Alexei Starovoitov 2019-10-15 4748 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/[email protected] _______________________________________________ kbuild mailing list -- [email protected] To unsubscribe send an email to [email protected]
