Re: [PATCH bpf-next 06/10] selftests/bpf: Test BTF_KIND_DECL_TAG for deduplication

Yonghong Song <yhs@xxxxxx> · Thu, 11 Nov 2021 11:13:33 -0800

On 11/11/21 10:49 AM, Andrii Nakryiko wrote:
On Tue, Nov 9, 2021 at 9:21 PM Yonghong Song <yhs@xxxxxx> wrote:

Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
  tools/testing/selftests/bpf/prog_tests/btf.c | 46 ++++++++++++++++++--
  1 file changed, 42 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index ebd0ead5f4bc..91b19c41729f 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -6889,15 +6889,16 @@ const struct btf_dedup_test dedup_tests[] = {
                         BTF_RESTRICT_ENC(8),                                            /* [11] restrict */
                         BTF_FUNC_PROTO_ENC(1, 2),                                       /* [12] func_proto */
                                 BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
-                               BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 8),
+                               BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 18),
                         BTF_FUNC_ENC(NAME_TBD, 12),                                     /* [13] func */
                         BTF_TYPE_FLOAT_ENC(NAME_TBD, 2),                                /* [14] float */
                         BTF_DECL_TAG_ENC(NAME_TBD, 13, -1),                             /* [15] decl_tag */
                         BTF_DECL_TAG_ENC(NAME_TBD, 13, 1),                              /* [16] decl_tag */
                         BTF_DECL_TAG_ENC(NAME_TBD, 7, -1),                              /* [17] decl_tag */
+                       BTF_TYPE_TAG_ENC(NAME_TBD, 8),                                  /* [18] type_tag */
                         BTF_END_RAW,
                 },
-               BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q"),
+               BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q\0R"),
         },
         .expect = {
                 .raw_types = {
@@ -6918,15 +6919,16 @@ const struct btf_dedup_test dedup_tests[] = {
                         BTF_RESTRICT_ENC(8),                                            /* [11] restrict */
                         BTF_FUNC_PROTO_ENC(1, 2),                                       /* [12] func_proto */
                                 BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
-                               BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 8),
+                               BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 18),
                         BTF_FUNC_ENC(NAME_TBD, 12),                                     /* [13] func */
                         BTF_TYPE_FLOAT_ENC(NAME_TBD, 2),                                /* [14] float */
                         BTF_DECL_TAG_ENC(NAME_TBD, 13, -1),                             /* [15] decl_tag */
                         BTF_DECL_TAG_ENC(NAME_TBD, 13, 1),                              /* [16] decl_tag */
                         BTF_DECL_TAG_ENC(NAME_TBD, 7, -1),                              /* [17] decl_tag */
+                       BTF_TYPE_TAG_ENC(NAME_TBD, 8),                                  /* [18] type_tag */
                         BTF_END_RAW,
                 },
-               BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q"),
+               BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P\0Q\0R"),
         },
         .opts = {
                 .dont_resolve_fwds = false,
@@ -7254,6 +7256,42 @@ const struct btf_dedup_test dedup_tests[] = {
                 .dont_resolve_fwds = false,
         },
  },
+{
+       .descr = "dedup: btf_tag_type",
+       .input = {
+               .raw_types = {
+                       /* int */
+                       BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
+                       /* tag: tag1, tag2 */
+                       BTF_TYPE_TAG_ENC(NAME_NTH(1), 1),               /* [2] */
+                       BTF_TYPE_TAG_ENC(NAME_NTH(2), 2),               /* [3] */
+                       BTF_PTR_ENC(3),                                 /* [4] */
+                       /* tag: tag1, tag2 */
+                       BTF_TYPE_TAG_ENC(NAME_NTH(1), 1),               /* [5] */
+                       BTF_TYPE_TAG_ENC(NAME_NTH(2), 5),               /* [6] */
+                       BTF_PTR_ENC(6),                                 /* [7] */
+                       /* tag: tag1 */
+                       BTF_TYPE_TAG_ENC(NAME_NTH(1), 1),               /* [8] */
+                       BTF_PTR_ENC(8),                                 /* [9] */
+                       BTF_END_RAW,
+               },
+               BTF_STR_SEC("\0tag1\0tag2"),
+       },

Can you please add a test for two more situations:

First, like this:

tag1 -> tag2 -> int
tag1 -> int

tag1's shouldn't be deduped

Second, like this

tag1 -> tag2 -> int
tag2 -> tag1 -> int

Nothing gets deduped.

Actually, also third situation:

tag1 -> int
tag1 -> long

Nothing gets deduped.

That will document expected behavior.

Will do.


Thanks.

+       .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_TAG_ENC(NAME_NTH(2), 2),               /* [3] */
+                       BTF_PTR_ENC(3),                                 /* [4] */
+                       BTF_PTR_ENC(2),                                 /* [5] */
+                       BTF_END_RAW,
+               },
+               BTF_STR_SEC("\0tag1\0tag2"),
+       },
+       .opts = {
+               .dont_resolve_fwds = false,
+       },
+},

  };

--
2.30.2







