selftests/bpf: Test new btf__add_btf() API

Add a test that validates that btf__add_btf() API is correctly copying
all the types from the source BTF into destination BTF object and
adjusts type IDs and string offsets properly.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211006051107.17921-4-andrii@kernel.org

diff --git a/tools/testing/selftests/bpf/prog_tests/btf_write.c b/tools/testing/selftests/bpf/prog_tests/btf_write.c
index aa45056..886e0fc 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/btf_write.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_write.c
@@ -342,8 +342,94 @@ static void test_btf_add()
        btf__free(btf);
 }
 
+static void test_btf_add_btf()
+{
+       struct btf *btf1 = NULL, *btf2 = NULL;
+       int id;
+
+       btf1 = btf__new_empty();
+       if (!ASSERT_OK_PTR(btf1, "btf1"))
+               return;
+
+       btf2 = btf__new_empty();
+       if (!ASSERT_OK_PTR(btf2, "btf2"))
+               goto cleanup;
+
+       gen_btf(btf1);
+       gen_btf(btf2);
+
+       id = btf__add_btf(btf1, btf2);
+       if (!ASSERT_EQ(id, 20, "id"))
+               goto cleanup;
+
+       VALIDATE_RAW_BTF(
+               btf1,
+               "[1] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+               "[2] PTR '(anon)' type_id=1",
+               "[3] CONST '(anon)' type_id=5",
+               "[4] VOLATILE '(anon)' type_id=3",
+               "[5] RESTRICT '(anon)' type_id=4",
+               "[6] ARRAY '(anon)' type_id=2 index_type_id=1 nr_elems=10",
+               "[7] STRUCT 's1' size=8 vlen=2\n"
+               "\t'f1' type_id=1 bits_offset=0\n"
+               "\t'f2' type_id=1 bits_offset=32 bitfield_size=16",
+               "[8] UNION 'u1' size=8 vlen=1\n"
+               "\t'f1' type_id=1 bits_offset=0 bitfield_size=16",
+               "[9] ENUM 'e1' size=4 vlen=2\n"
+               "\t'v1' val=1\n"
+               "\t'v2' val=2",
+               "[10] FWD 'struct_fwd' fwd_kind=struct",
+               "[11] FWD 'union_fwd' fwd_kind=union",
+               "[12] ENUM 'enum_fwd' size=4 vlen=0",
+               "[13] TYPEDEF 'typedef1' type_id=1",
+               "[14] FUNC 'func1' type_id=15 linkage=global",
+               "[15] FUNC_PROTO '(anon)' ret_type_id=1 vlen=2\n"
+               "\t'p1' type_id=1\n"
+               "\t'p2' type_id=2",
+               "[16] VAR 'var1' type_id=1, linkage=global-alloc",
+               "[17] DATASEC 'datasec1' size=12 vlen=1\n"
+               "\ttype_id=1 offset=4 size=8",
+               "[18] TAG 'tag1' type_id=16 component_idx=-1",
+               "[19] TAG 'tag2' type_id=14 component_idx=1",
+
+               /* types appended from the second BTF */
+               "[20] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
+               "[21] PTR '(anon)' type_id=20",
+               "[22] CONST '(anon)' type_id=24",
+               "[23] VOLATILE '(anon)' type_id=22",
+               "[24] RESTRICT '(anon)' type_id=23",
+               "[25] ARRAY '(anon)' type_id=21 index_type_id=20 nr_elems=10",
+               "[26] STRUCT 's1' size=8 vlen=2\n"
+               "\t'f1' type_id=20 bits_offset=0\n"
+               "\t'f2' type_id=20 bits_offset=32 bitfield_size=16",
+               "[27] UNION 'u1' size=8 vlen=1\n"
+               "\t'f1' type_id=20 bits_offset=0 bitfield_size=16",
+               "[28] ENUM 'e1' size=4 vlen=2\n"
+               "\t'v1' val=1\n"
+               "\t'v2' val=2",
+               "[29] FWD 'struct_fwd' fwd_kind=struct",
+               "[30] FWD 'union_fwd' fwd_kind=union",
+               "[31] ENUM 'enum_fwd' size=4 vlen=0",
+               "[32] TYPEDEF 'typedef1' type_id=20",
+               "[33] FUNC 'func1' type_id=34 linkage=global",
+               "[34] FUNC_PROTO '(anon)' ret_type_id=20 vlen=2\n"
+               "\t'p1' type_id=20\n"
+               "\t'p2' type_id=21",
+               "[35] VAR 'var1' type_id=20, linkage=global-alloc",
+               "[36] DATASEC 'datasec1' size=12 vlen=1\n"
+               "\ttype_id=20 offset=4 size=8",
+               "[37] TAG 'tag1' type_id=35 component_idx=-1",
+               "[38] TAG 'tag2' type_id=33 component_idx=1");
+
+cleanup:
+       btf__free(btf1);
+       btf__free(btf2);
+}
+
 void test_btf_write()
 {
        if (test__start_subtest("btf_add"))
                test_btf_add();
+       if (test__start_subtest("btf_add_btf"))
+               test_btf_add_btf();
 }