It should trigger a WARN_ON_ONCE in btf_type_id_size. btf_func_proto_check kernel/bpf/btf.c:4447 [inline] btf_check_all_types kernel/bpf/btf.c:4723 [inline] btf_parse_type_sec kernel/bpf/btf.c:4752 [inline] btf_parse kernel/bpf/btf.c:5026 [inline] btf_new_fd+0x1926/0x1e70 kernel/bpf/btf.c:6892 bpf_btf_load kernel/bpf/syscall.c:4324 [inline] __sys_bpf+0xb7d/0x4cf0 kernel/bpf/syscall.c:5010 __do_sys_bpf kernel/bpf/syscall.c:5069 [inline] __se_sys_bpf kernel/bpf/syscall.c:5067 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:5067 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Cc: Yonghong Song <yhs@xxxxxx> Cc: Martin KaFai Lau <martin.lau@xxxxxxxxxx> Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx> --- tools/testing/selftests/bpf/prog_tests/btf.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c index 127b8caa3dc1..24dd6214394e 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf.c +++ b/tools/testing/selftests/bpf/prog_tests/btf.c @@ -3935,6 +3935,19 @@ static struct btf_raw_test raw_tests[] = { .btf_load_err = true, .err_str = "Invalid type_id", }, +{ + .descr = "decl_tag test #16, func proto, return type", + .raw_types = { + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */ + BTF_VAR_ENC(NAME_TBD, 1, 0), /* [2] */ + BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), 2), (-1), /* [3] */ + BTF_FUNC_PROTO_ENC(3, 0), /* [4] */ + BTF_END_RAW, + }, + BTF_STR_SEC("\0local\0tag1"), + .btf_load_err = true, + .err_str = "Invalid return type", +}, { .descr = "type_tag test #1", .raw_types = { -- 2.38.0.413.g74048e4d9e-goog