1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/err.h>
4#include <string.h>
5#include <bpf/btf.h>
6#include <bpf/libbpf.h>
7#include <linux/btf.h>
8#include <linux/kernel.h>
9#define CONFIG_DEBUG_INFO_BTF
10#include <linux/btf_ids.h>
11#include "test_progs.h"
12
13static int duration;
14
15struct symbol {
16	const char	*name;
17	int		 type;
18	int		 id;
19};
20
21struct symbol test_symbols[] = {
22	{ "unused",  BTF_KIND_UNKN,     0 },
23	{ "S",       BTF_KIND_TYPEDEF, -1 },
24	{ "T",       BTF_KIND_TYPEDEF, -1 },
25	{ "U",       BTF_KIND_TYPEDEF, -1 },
26	{ "S",       BTF_KIND_STRUCT,  -1 },
27	{ "U",       BTF_KIND_UNION,   -1 },
28	{ "func",    BTF_KIND_FUNC,    -1 },
29};
30
31/* Align the .BTF_ids section to 4 bytes */
32asm (
33".pushsection " BTF_IDS_SECTION " ,\"a\"; \n"
34".balign 4, 0;                            \n"
35".popsection;                             \n");
36
37BTF_ID_LIST(test_list_local)
38BTF_ID_UNUSED
39BTF_ID(typedef, S)
40BTF_ID(typedef, T)
41BTF_ID(typedef, U)
42BTF_ID(struct,  S)
43BTF_ID(union,   U)
44BTF_ID(func,    func)
45
46extern __u32 test_list_global[];
47BTF_ID_LIST_GLOBAL(test_list_global, 1)
48BTF_ID_UNUSED
49BTF_ID(typedef, S)
50BTF_ID(typedef, T)
51BTF_ID(typedef, U)
52BTF_ID(struct,  S)
53BTF_ID(union,   U)
54BTF_ID(func,    func)
55
56BTF_SET_START(test_set)
57BTF_ID(typedef, S)
58BTF_ID(typedef, T)
59BTF_ID(typedef, U)
60BTF_ID(struct,  S)
61BTF_ID(union,   U)
62BTF_ID(func,    func)
63BTF_SET_END(test_set)
64
65static int
66__resolve_symbol(struct btf *btf, int type_id)
67{
68	const struct btf_type *type;
69	const char *str;
70	unsigned int i;
71
72	type = btf__type_by_id(btf, type_id);
73	if (!type) {
74		PRINT_FAIL("Failed to get type for ID %d\n", type_id);
75		return -1;
76	}
77
78	for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
79		if (test_symbols[i].id >= 0)
80			continue;
81
82		if (BTF_INFO_KIND(type->info) != test_symbols[i].type)
83			continue;
84
85		str = btf__name_by_offset(btf, type->name_off);
86		if (!str) {
87			PRINT_FAIL("Failed to get name for BTF ID %d\n", type_id);
88			return -1;
89		}
90
91		if (!strcmp(str, test_symbols[i].name))
92			test_symbols[i].id = type_id;
93	}
94
95	return 0;
96}
97
98static int resolve_symbols(void)
99{
100	struct btf *btf;
101	int type_id;
102	__u32 nr;
103
104	btf = btf__parse_elf("btf_data.bpf.o", NULL);
105	if (CHECK(libbpf_get_error(btf), "resolve",
106		  "Failed to load BTF from btf_data.o\n"))
107		return -1;
108
109	nr = btf__type_cnt(btf);
110
111	for (type_id = 1; type_id < nr; type_id++) {
112		if (__resolve_symbol(btf, type_id))
113			break;
114	}
115
116	btf__free(btf);
117	return 0;
118}
119
120void test_resolve_btfids(void)
121{
122	__u32 *test_list, *test_lists[] = { test_list_local, test_list_global };
123	unsigned int i, j;
124	int ret = 0;
125
126	if (resolve_symbols())
127		return;
128
129	/* Check BTF_ID_LIST(test_list_local) and
130	 * BTF_ID_LIST_GLOBAL(test_list_global) IDs
131	 */
132	for (j = 0; j < ARRAY_SIZE(test_lists); j++) {
133		test_list = test_lists[j];
134		for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
135			ret = CHECK(test_list[i] != test_symbols[i].id,
136				    "id_check",
137				    "wrong ID for %s (%d != %d)\n",
138				    test_symbols[i].name,
139				    test_list[i], test_symbols[i].id);
140			if (ret)
141				return;
142		}
143	}
144
145	/* Check BTF_SET_START(test_set) IDs */
146	for (i = 0; i < test_set.cnt; i++) {
147		bool found = false;
148
149		for (j = 0; j < ARRAY_SIZE(test_symbols); j++) {
150			if (test_symbols[j].id != test_set.ids[i])
151				continue;
152			found = true;
153			break;
154		}
155
156		ret = CHECK(!found, "id_check",
157			    "ID %d not found in test_symbols\n",
158			    test_set.ids[i]);
159		if (ret)
160			break;
161
162		if (i > 0) {
163			if (!ASSERT_LE(test_set.ids[i - 1], test_set.ids[i], "sort_check"))
164				return;
165		}
166	}
167}
168