tools/bpf: remove btf__get_strings() superseded by raw data API

Now that we have btf__get_raw_data() it's trivial for tests to iterate
over all strings for testing purposes, which eliminates the need for
btf__get_strings() API.
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/btf.c

@@ -449,13 +449,6 @@ const void *btf__get_raw_data(const struct btf *btf, __u32 *size)
 	return btf->data;
 }
 
-void btf__get_strings(const struct btf *btf, const char **strings,
-		      __u32 *str_len)
-{
-	*strings = btf->strings;
-	*str_len = btf->hdr->str_len;
-}
-
 const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
 {
 	if (offset < btf->hdr->str_len)

tools/lib/bpf/btf.h

@@ -67,8 +67,6 @@ LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__fd(const struct btf *btf);
 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
-LIBBPF_API void btf__get_strings(const struct btf *btf, const char **strings,
-				 __u32 *str_len);
 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,

tools/lib/bpf/libbpf.map

@@ -137,7 +137,6 @@ LIBBPF_0.0.2 {
 		btf__get_map_kv_tids;
 		btf__get_nr_types;
 		btf__get_raw_data;
-		btf__get_strings;
 		btf__load;
 		btf_ext__free;
 		btf_ext__func_info_rec_size;

tools/testing/selftests/bpf/test_btf.c

@@ -5882,15 +5882,17 @@ static void dump_btf_strings(const char *strs, __u32 len)
 static int do_test_dedup(unsigned int test_num)
 {
 	const struct btf_dedup_test *test = &dedup_tests[test_num - 1];
-	int err = 0, i;
-	__u32 test_nr_types, expect_nr_types, test_str_len, expect_str_len;
-	void *raw_btf;
-	unsigned int raw_btf_size;
+	__u32 test_nr_types, expect_nr_types, test_btf_size, expect_btf_size;
+	const struct btf_header *test_hdr, *expect_hdr;
 	struct btf *test_btf = NULL, *expect_btf = NULL;
+	const void *test_btf_data, *expect_btf_data;
 	const char *ret_test_next_str, *ret_expect_next_str;
 	const char *test_strs, *expect_strs;
 	const char *test_str_cur, *test_str_end;
 	const char *expect_str_cur, *expect_str_end;
+	unsigned int raw_btf_size;
+	void *raw_btf;
+	int err = 0, i;
 
 	fprintf(stderr, "BTF dedup test[%u] (%s):", test_num, test->descr);
 
@@ -5927,23 +5929,34 @@ static int do_test_dedup(unsigned int test_num)
 		goto done;
 	}
 
-	btf__get_strings(test_btf, &test_strs, &test_str_len);
-	btf__get_strings(expect_btf, &expect_strs, &expect_str_len);
-	if (CHECK(test_str_len != expect_str_len,
-		  "test_str_len:%u != expect_str_len:%u",
-		  test_str_len, expect_str_len)) {
+	test_btf_data = btf__get_raw_data(test_btf, &test_btf_size);
+	expect_btf_data = btf__get_raw_data(expect_btf, &expect_btf_size);
+	if (CHECK(test_btf_size != expect_btf_size,
+		  "test_btf_size:%u != expect_btf_size:%u",
+		  test_btf_size, expect_btf_size)) {
+		err = -1;
+		goto done;
+	}
+
+	test_hdr = test_btf_data;
+	test_strs = test_btf_data + test_hdr->str_off;
+	expect_hdr = expect_btf_data;
+	expect_strs = expect_btf_data + expect_hdr->str_off;
+	if (CHECK(test_hdr->str_len != expect_hdr->str_len,
+		  "test_hdr->str_len:%u != expect_hdr->str_len:%u",
+		  test_hdr->str_len, expect_hdr->str_len)) {
 		fprintf(stderr, "\ntest strings:\n");
-		dump_btf_strings(test_strs, test_str_len);
+		dump_btf_strings(test_strs, test_hdr->str_len);
 		fprintf(stderr, "\nexpected strings:\n");
-		dump_btf_strings(expect_strs, expect_str_len);
+		dump_btf_strings(expect_strs, expect_hdr->str_len);
 		err = -1;
 		goto done;
 	}
 
 	test_str_cur = test_strs;
-	test_str_end = test_strs + test_str_len;
+	test_str_end = test_strs + test_hdr->str_len;
 	expect_str_cur = expect_strs;
-	expect_str_end = expect_strs + expect_str_len;
+	expect_str_end = expect_strs + expect_hdr->str_len;
 	while (test_str_cur < test_str_end && expect_str_cur < expect_str_end) {
 		size_t test_len, expect_len;