On 02/11/2022 11:09, Eduard Zingerman wrote:
> Tests to verify the following behavior of `btf_dedup_resolve_fwds`:
> - remapping for struct forward declarations;
> - remapping for union forward declarations;
> - no remapping if forward declaration kind does not match similarly
> named struct or union declaration;
> - no remapping if forward declaration name is ambiguous;
> - base ids are considered for fwd resolution in split btf scenario.
>
> Signed-off-by: Eduard Zingerman <eddyz87@xxxxxxxxx>
Really nice having positive and negative tests here!
Reviewed-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
> ---
> tools/testing/selftests/bpf/prog_tests/btf.c | 152 ++++++++++++++++++
> .../bpf/prog_tests/btf_dedup_split.c | 45 ++++--
> 2 files changed, 182 insertions(+), 15 deletions(-)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
> index 127b8caa3dc1..f14020d51ab9 100644
> --- a/tools/testing/selftests/bpf/prog_tests/btf.c
> +++ b/tools/testing/selftests/bpf/prog_tests/btf.c
> @@ -7598,6 +7598,158 @@ static struct btf_dedup_test dedup_tests[] = {
> BTF_STR_SEC("\0e1\0e1_val"),
> },
> },
> +{
> + .descr = "dedup: standalone fwd declaration struct",
> + /*
> + * // CU 1:
> + * struct foo { int x; };
> + * struct foo *a;
> + *
> + * // CU 2:
> + * struct foo;
> + * struct foo *b;
> + */
> + .input = {
> + .raw_types = {
> + BTF_STRUCT_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_FWD_ENC(NAME_TBD, 0), /* [4] */
> + BTF_PTR_ENC(4), /* [5] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x"),
> + },
> + .expect = {
> + .raw_types = {
> + BTF_STRUCT_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x"),
> + },
> +},
> +{
> + .descr = "dedup: standalone fwd declaration union",
> + /*
> + * // CU 1:
> + * union foo { int x; };
> + * union foo *another_global;
> + *
> + * // CU 2:
> + * union foo;
> + * union foo *some_global;
> + */
> + .input = {
> + .raw_types = {
> + BTF_UNION_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_FWD_ENC(NAME_TBD, 1), /* [4] */
> + BTF_PTR_ENC(4), /* [5] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x"),
> + },
> + .expect = {
> + .raw_types = {
> + BTF_UNION_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x"),
> + },
> +},
> +{
> + .descr = "dedup: standalone fwd declaration wrong kind",
> + /*
> + * // CU 1:
> + * struct foo { int x; };
> + * struct foo *b;
> + *
> + * // CU 2:
> + * union foo;
> + * union foo *a;
> + */
> + .input = {
> + .raw_types = {
> + BTF_STRUCT_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_FWD_ENC(NAME_TBD, 1), /* [4] */
> + BTF_PTR_ENC(4), /* [5] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x"),
> + },
> + .expect = {
> + .raw_types = {
> + BTF_STRUCT_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_FWD_ENC(NAME_TBD, 1), /* [4] */
> + BTF_PTR_ENC(4), /* [5] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x"),
> + },
> +},
> +{
> + .descr = "dedup: standalone fwd declaration name conflict",
> + /*
> + * // CU 1:
> + * struct foo { int x; };
> + * struct foo *a;
> + *
> + * // CU 2:
> + * struct foo;
> + * struct foo *b;
> + *
> + * // CU 3:
> + * struct foo { int x; int y; };
> + * struct foo *c;
> + */
> + .input = {
> + .raw_types = {
> + BTF_STRUCT_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_FWD_ENC(NAME_TBD, 0), /* [4] */
> + BTF_PTR_ENC(4), /* [5] */
> + BTF_STRUCT_ENC(NAME_NTH(1), 2, 8), /* [6] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_MEMBER_ENC(NAME_NTH(3), 2, 0),
> + BTF_PTR_ENC(6), /* [7] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x\0y"),
> + },
> + .expect = {
> + .raw_types = {
> + BTF_STRUCT_ENC(NAME_NTH(1), 1, 4), /* [1] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4), /* [2] */
> + BTF_PTR_ENC(1), /* [3] */
> + BTF_FWD_ENC(NAME_TBD, 0), /* [4] */
> + BTF_PTR_ENC(4), /* [5] */
> + BTF_STRUCT_ENC(NAME_NTH(1), 2, 8), /* [6] */
> + BTF_MEMBER_ENC(NAME_NTH(2), 2, 0),
> + BTF_MEMBER_ENC(NAME_NTH(3), 2, 0),
> + BTF_PTR_ENC(6), /* [7] */
> + BTF_END_RAW,
> + },
> + BTF_STR_SEC("\0foo\0x\0y"),
> + },
> +},
>
> };
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> index 90aac437576d..d9024c7a892a 100644
> --- a/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> +++ b/tools/testing/selftests/bpf/prog_tests/btf_dedup_split.c
> @@ -141,6 +141,10 @@ static void test_split_fwd_resolve() {
> btf__add_field(btf1, "f2", 3, 64, 0); /* struct s2 *f2; */
> /* } */
> btf__add_struct(btf1, "s2", 4); /* [5] struct s2 { */
> + btf__add_field(btf1, "f1", 1, 0, 0); /* int f1; */
> + /* } */
> + /* keep this not a part of type the graph to test btf_dedup_resolve_fwds */
> + btf__add_struct(btf1, "s3", 4); /* [6] struct s3 { */
> btf__add_field(btf1, "f1", 1, 0, 0); /* int f1; */
> /* } */
>
> @@ -153,20 +157,24 @@ static void test_split_fwd_resolve() {
> "\t'f1' type_id=2 bits_offset=0\n"
> "\t'f2' type_id=3 bits_offset=64",
> "[5] STRUCT 's2' size=4 vlen=1\n"
> + "\t'f1' type_id=1 bits_offset=0",
> + "[6] STRUCT 's3' size=4 vlen=1\n"
> "\t'f1' type_id=1 bits_offset=0");
>
> btf2 = btf__new_empty_split(btf1);
> if (!ASSERT_OK_PTR(btf2, "empty_split_btf"))
> goto cleanup;
>
> - btf__add_int(btf2, "int", 4, BTF_INT_SIGNED); /* [6] int */
> - btf__add_ptr(btf2, 10); /* [7] ptr to struct s1 */
> - btf__add_fwd(btf2, "s2", BTF_FWD_STRUCT); /* [8] fwd for struct s2 */
> - btf__add_ptr(btf2, 8); /* [9] ptr to fwd struct s2 */
> - btf__add_struct(btf2, "s1", 16); /* [10] struct s1 { */
> - btf__add_field(btf2, "f1", 7, 0, 0); /* struct s1 *f1; */
> - btf__add_field(btf2, "f2", 9, 64, 0); /* struct s2 *f2; */
> + btf__add_int(btf2, "int", 4, BTF_INT_SIGNED); /* [7] int */
> + btf__add_ptr(btf2, 11); /* [8] ptr to struct s1 */
> + btf__add_fwd(btf2, "s2", BTF_FWD_STRUCT); /* [9] fwd for struct s2 */
> + btf__add_ptr(btf2, 9); /* [10] ptr to fwd struct s2 */
> + btf__add_struct(btf2, "s1", 16); /* [11] struct s1 { */
> + btf__add_field(btf2, "f1", 8, 0, 0); /* struct s1 *f1; */
> + btf__add_field(btf2, "f2", 10, 64, 0); /* struct s2 *f2; */
> /* } */
> + btf__add_fwd(btf2, "s3", BTF_FWD_STRUCT); /* [12] fwd for struct s3 */
> + btf__add_ptr(btf2, 12); /* [13] ptr to struct s1 */
>
> VALIDATE_RAW_BTF(
> btf2,
> @@ -178,13 +186,17 @@ static void test_split_fwd_resolve() {
> "\t'f2' type_id=3 bits_offset=64",
> "[5] STRUCT 's2' size=4 vlen=1\n"
> "\t'f1' type_id=1 bits_offset=0",
> - "[6] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
> - "[7] PTR '(anon)' type_id=10",
> - "[8] FWD 's2' fwd_kind=struct",
> - "[9] PTR '(anon)' type_id=8",
> - "[10] STRUCT 's1' size=16 vlen=2\n"
> - "\t'f1' type_id=7 bits_offset=0\n"
> - "\t'f2' type_id=9 bits_offset=64");
> + "[6] STRUCT 's3' size=4 vlen=1\n"
> + "\t'f1' type_id=1 bits_offset=0",
> + "[7] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
> + "[8] PTR '(anon)' type_id=11",
> + "[9] FWD 's2' fwd_kind=struct",
> + "[10] PTR '(anon)' type_id=9",
> + "[11] STRUCT 's1' size=16 vlen=2\n"
> + "\t'f1' type_id=8 bits_offset=0\n"
> + "\t'f2' type_id=10 bits_offset=64",
> + "[12] FWD 's3' fwd_kind=struct",
> + "[13] PTR '(anon)' type_id=12");
>
> err = btf__dedup(btf2, NULL);
> if (!ASSERT_OK(err, "btf_dedup"))
> @@ -199,7 +211,10 @@ static void test_split_fwd_resolve() {
> "\t'f1' type_id=2 bits_offset=0\n"
> "\t'f2' type_id=3 bits_offset=64",
> "[5] STRUCT 's2' size=4 vlen=1\n"
> - "\t'f1' type_id=1 bits_offset=0");
> + "\t'f1' type_id=1 bits_offset=0",
> + "[6] STRUCT 's3' size=4 vlen=1\n"
> + "\t'f1' type_id=1 bits_offset=0",
> + "[7] PTR '(anon)' type_id=6");
>
> cleanup:
> btf__free(btf2);
>
