From: Andrii Nakryiko <andriin@xxxxxx>
This patch adds specific test exposing bug in btf_dedup_is_equiv() when
comparing candidate VOID type to a non-VOID canonical type. It's
important for canonical type to be anonymous, otherwise name equality
check will do the right thing and will exit early.
Signed-off-by: Andrii Nakryiko <andriin@xxxxxx>
---
tools/testing/selftests/bpf/test_btf.c | 47 ++++++++++++++++++++++++++
1 file changed, 47 insertions(+)
diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c
index 23e3b314ca60..ec5794e4205b 100644
--- a/tools/testing/selftests/bpf/test_btf.c
+++ b/tools/testing/selftests/bpf/test_btf.c
@@ -5776,6 +5776,53 @@ const struct btf_dedup_test dedup_tests[] = {
.dedup_table_size = 1, /* force hash collisions */
},
},
+{
+ .descr = "dedup: void equiv check",
+ /*
+ * // CU 1:
+ * struct s {
+ * struct {} *x;
+ * };
+ * // CU 2:
+ * struct s {
+ * int *x;
+ * };
+ */
+ .input = {
+ .raw_types = {
+ /* CU 1 */
+ BTF_STRUCT_ENC(0, 0, 1), /* [1] struct {} */
+ BTF_PTR_ENC(1), /* [2] ptr -> [1] */
+ BTF_STRUCT_ENC(NAME_NTH(1), 1, 8), /* [3] struct s */
+ BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
+ /* CU 2 */
+ BTF_PTR_ENC(0), /* [4] ptr -> void */
+ BTF_STRUCT_ENC(NAME_NTH(1), 1, 8), /* [5] struct s */
+ BTF_MEMBER_ENC(NAME_NTH(2), 4, 0),
+ BTF_END_RAW,
+ },
+ BTF_STR_SEC("\0s\0x"),
+ },
+ .expect = {
+ .raw_types = {
+ /* CU 1 */
+ BTF_STRUCT_ENC(0, 0, 1), /* [1] struct {} */
+ BTF_PTR_ENC(1), /* [2] ptr -> [1] */
+ BTF_STRUCT_ENC(NAME_NTH(1), 1, 8), /* [3] struct s */
+ BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
+ /* CU 2 */
+ BTF_PTR_ENC(0), /* [4] ptr -> void */
+ BTF_STRUCT_ENC(NAME_NTH(1), 1, 8), /* [5] struct s */
+ BTF_MEMBER_ENC(NAME_NTH(2), 4, 0),
+ BTF_END_RAW,
+ },
+ BTF_STR_SEC("\0s\0x"),
+ },
+ .opts = {
+ .dont_resolve_fwds = false,
+ .dedup_table_size = 1, /* force hash collisions */
+ },
+},
{
.descr = "dedup: all possible kinds (no duplicates)",
.input = {
--
2.17.1
