selftests/bpf: Add a dedup selftest with equivalent structure types

Without previous libbpf patch, the following error will occur:

  $ ./test_progs -t btf
  ...
  do_test_dedup:FAIL:check btf_dedup failed errno:-22#13/205 btf/dedup: btf_type_tag #5, struct:FAIL

And the previous libbpf patch fixed the issue.

Signed-off-by: Yonghong Song <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

tools/testing/selftests/bpf/prog_tests/btf.c

@@ -7352,6 +7352,32 @@ static struct btf_dedup_test dedup_tests[] = {
  BTF_STR_SEC("\0tag1"),
  },
 },
+{
+ .descr = "dedup: btf_type_tag #5, struct",
+ .input = {
+ .raw_types = {
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ BTF_TYPE_TAG_ENC(NAME_NTH(1), 1), /* [2] */
+ BTF_TYPE_ENC(NAME_NTH(2), BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 1), 4), /* [3] */
+ BTF_MEMBER_ENC(NAME_NTH(3), 2, BTF_MEMBER_OFFSET(0, 0)),
+ BTF_TYPE_TAG_ENC(NAME_NTH(1), 1), /* [4] */
+ BTF_TYPE_ENC(NAME_NTH(2), BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 1), 4), /* [5] */
+ BTF_MEMBER_ENC(NAME_NTH(3), 4, BTF_MEMBER_OFFSET(0, 0)),
+ BTF_END_RAW,
+ },
+ BTF_STR_SEC("\0tag1\0t\0m"),
+ },
+ .expect = {
+ .raw_types = {
+ BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [1] */
+ BTF_TYPE_TAG_ENC(NAME_NTH(1), 1), /* [2] */
+ BTF_TYPE_ENC(NAME_NTH(2), BTF_INFO_ENC(BTF_KIND_STRUCT, 1, 1), 4), /* [3] */
+ BTF_MEMBER_ENC(NAME_NTH(3), 2, BTF_MEMBER_OFFSET(0, 0)),
+ BTF_END_RAW,
+ },
+ BTF_STR_SEC("\0tag1\0t\0m"),
+ },
+},
 
 };