Commit 02f5e7c1 authored by Alan Maguire's avatar Alan Maguire Committed by Andrii Nakryiko
Browse files

selftests/bpf: Test multi-split BTF 



Extend split BTF test to cover case where we create split BTF on top of
existing split BTF and add info to it; ensure that such BTF can be
created and handled by searching within it, dumping/comparing to expected.

Signed-off-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250519165935.261614-3-alan.maguire@oracle.com
parent 4e29128a

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

+52 −6
Original line number Diff line number Diff line
@@ -12,10 +12,11 @@ static void btf_dump_printf(void *ctx, const char *fmt, va_list args) 
	vfprintf(ctx, fmt, args);

}



void test_btf_split() {

static void __test_btf_split(bool multi)

{

	struct btf_dump *d = NULL;

	const struct btf_type *t;

	struct btf *btf1, *btf2;

	struct btf *btf1, *btf2, *btf3 = NULL;

	int str_off, i, err;



	btf1 = btf__new_empty();
@@ -63,14 +64,46 @@ void test_btf_split() { 
	ASSERT_EQ(btf_vlen(t), 3, "split_struct_vlen");

	ASSERT_STREQ(btf__str_by_offset(btf2, t->name_off), "s2", "split_struct_name");



	if (multi) {

		btf3 = btf__new_empty_split(btf2);

		if (!ASSERT_OK_PTR(btf3, "multi_split_btf"))

			goto cleanup;

	} else {

		btf3 = btf2;

	}



	btf__add_union(btf3, "u1", 16);			/* [5] union u1 {	*/

	btf__add_field(btf3, "f1", 4, 0, 0);		/*	struct s2 f1;	*/

	btf__add_field(btf3, "uf2", 1, 0, 0);		/*	int f2;		*/

							/* } */



	if (multi) {

		t = btf__type_by_id(btf2, 5);

		ASSERT_NULL(t, "multisplit_type_in_first_split");

	}



	t = btf__type_by_id(btf3, 5);

	if (!ASSERT_OK_PTR(t, "split_union_type"))

		goto cleanup;

	ASSERT_EQ(btf_is_union(t), true, "split_union_kind");

	ASSERT_EQ(btf_vlen(t), 2, "split_union_vlen");

	ASSERT_STREQ(btf__str_by_offset(btf3, t->name_off), "u1", "split_union_name");

	ASSERT_EQ(btf__type_cnt(btf3), 6, "split_type_cnt");



	t = btf__type_by_id(btf3, 1);

	if (!ASSERT_OK_PTR(t, "split_base_type"))

		goto cleanup;

	ASSERT_EQ(btf_is_int(t), true, "split_base_int");

	ASSERT_STREQ(btf__str_by_offset(btf3, t->name_off), "int", "split_base_type_name");



	/* BTF-to-C dump of split BTF */

	dump_buf_file = open_memstream(&dump_buf, &dump_buf_sz);

	if (!ASSERT_OK_PTR(dump_buf_file, "dump_memstream"))

		return;

	d = btf_dump__new(btf2, btf_dump_printf, dump_buf_file, NULL);

	d = btf_dump__new(btf3, btf_dump_printf, dump_buf_file, NULL);

	if (!ASSERT_OK_PTR(d, "btf_dump__new"))

		goto cleanup;

	for (i = 1; i < btf__type_cnt(btf2); i++) {

	for (i = 1; i < btf__type_cnt(btf3); i++) {

		err = btf_dump__dump_type(d, i);

		ASSERT_OK(err, "dump_type_ok");

	}
@@ -79,12 +112,15 @@ void test_btf_split() { 
	ASSERT_STREQ(dump_buf,

"struct s1 {\n"

"	int f1;\n"

"};\n"

"\n"

"};\n\n"

"struct s2 {\n"

"	struct s1 f1;\n"

"	int f2;\n"

"	int *f3;\n"

"};\n\n"

"union u1 {\n"

"	struct s2 f1;\n"

"	int uf2;\n"

"};\n\n", "c_dump");



cleanup:
@@ -94,4 +130,14 @@ void test_btf_split() { 
	btf_dump__free(d);

	btf__free(btf1);

	btf__free(btf2);

	if (btf2 != btf3)

		btf__free(btf3);

}



void test_btf_split(void)

{

	if (test__start_subtest("single_split"))

		__test_btf_split(false);

	if (test__start_subtest("multi_split"))

		__test_btf_split(true);

}