selftests/bpf: Test libbpf API function btf__add_tag()

Add btf_write tests with btf__add_tag() function.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223036.247560-1-yhs@fb.com

diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c
index b692e6e..ce103fb 100644 (file)
--- a/tools/testing/selftests/bpf/btf_helpers.c
+++ b/tools/testing/selftests/bpf/btf_helpers.c
@@ -24,11 +24,12 @@ static const char * const btf_kind_str_mapping[] = {
        [BTF_KIND_VAR]          = "VAR",
        [BTF_KIND_DATASEC]      = "DATASEC",
        [BTF_KIND_FLOAT]        = "FLOAT",
+       [BTF_KIND_TAG]          = "TAG",
 };
 
 static const char *btf_kind_str(__u16 kind)
 {
-       if (kind > BTF_KIND_DATASEC)
+       if (kind > BTF_KIND_TAG)
                return "UNKNOWN";
        return btf_kind_str_mapping[kind];
 }
@@ -177,6 +178,10 @@ int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
        case BTF_KIND_FLOAT:
                fprintf(out, " size=%u", t->size);
                break;
+       case BTF_KIND_TAG:
+               fprintf(out, " type_id=%u component_idx=%d",
+                       t->type, btf_tag(t)->component_idx);
+               break;
        default:
                break;
        }

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_write.c b/tools/testing/selftests/bpf/prog_tests/btf_write.c
index 022c7d8..76548ee 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/btf_write.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_write.c
@@ -281,5 +281,26 @@ void test_btf_write() {
                     "[17] DATASEC 'datasec1' size=12 vlen=1\n"
                     "\ttype_id=1 offset=4 size=8", "raw_dump");
 
+       /* TAG */
+       id = btf__add_tag(btf, "tag1", 16, -1);
+       ASSERT_EQ(id, 18, "tag_id");
+       t = btf__type_by_id(btf, 18);
+       ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "tag1", "tag_value");
+       ASSERT_EQ(btf_kind(t), BTF_KIND_TAG, "tag_kind");
+       ASSERT_EQ(t->type, 16, "tag_type");
+       ASSERT_EQ(btf_tag(t)->component_idx, -1, "tag_component_idx");
+       ASSERT_STREQ(btf_type_raw_dump(btf, 18),
+                    "[18] TAG 'tag1' type_id=16 component_idx=-1", "raw_dump");
+
+       id = btf__add_tag(btf, "tag2", 14, 1);
+       ASSERT_EQ(id, 19, "tag_id");
+       t = btf__type_by_id(btf, 19);
+       ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "tag2", "tag_value");
+       ASSERT_EQ(btf_kind(t), BTF_KIND_TAG, "tag_kind");
+       ASSERT_EQ(t->type, 14, "tag_type");
+       ASSERT_EQ(btf_tag(t)->component_idx, 1, "tag_component_idx");
+       ASSERT_STREQ(btf_type_raw_dump(btf, 19),
+                    "[19] TAG 'tag2' type_id=14 component_idx=1", "raw_dump");
+
        btf__free(btf);
 }