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 
13 static int duration;
14 
15 struct symbol {
16 	const char	*name;
17 	int		 type;
18 	int		 id;
19 };
20 
21 struct 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 BTF_ID_LIST(test_list_local)
32 BTF_ID_UNUSED
33 BTF_ID(typedef, S)
34 BTF_ID(typedef, T)
35 BTF_ID(typedef, U)
36 BTF_ID(struct,  S)
37 BTF_ID(union,   U)
38 BTF_ID(func,    func)
39 
40 extern __u32 test_list_global[];
41 BTF_ID_LIST_GLOBAL(test_list_global)
42 BTF_ID_UNUSED
43 BTF_ID(typedef, S)
44 BTF_ID(typedef, T)
45 BTF_ID(typedef, U)
46 BTF_ID(struct,  S)
47 BTF_ID(union,   U)
48 BTF_ID(func,    func)
49 
50 static int
51 __resolve_symbol(struct btf *btf, int type_id)
52 {
53 	const struct btf_type *type;
54 	const char *str;
55 	unsigned int i;
56 
57 	type = btf__type_by_id(btf, type_id);
58 	if (!type) {
59 		PRINT_FAIL("Failed to get type for ID %d\n", type_id);
60 		return -1;
61 	}
62 
63 	for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
64 		if (test_symbols[i].id != -1)
65 			continue;
66 
67 		if (BTF_INFO_KIND(type->info) != test_symbols[i].type)
68 			continue;
69 
70 		str = btf__name_by_offset(btf, type->name_off);
71 		if (!str) {
72 			PRINT_FAIL("Failed to get name for BTF ID %d\n", type_id);
73 			return -1;
74 		}
75 
76 		if (!strcmp(str, test_symbols[i].name))
77 			test_symbols[i].id = type_id;
78 	}
79 
80 	return 0;
81 }
82 
83 static int resolve_symbols(void)
84 {
85 	struct btf *btf;
86 	int type_id;
87 	__u32 nr;
88 
89 	btf = btf__parse_elf("btf_data.o", NULL);
90 	if (CHECK(libbpf_get_error(btf), "resolve",
91 		  "Failed to load BTF from btf_data.o\n"))
92 		return -1;
93 
94 	nr = btf__get_nr_types(btf);
95 
96 	for (type_id = 1; type_id <= nr; type_id++) {
97 		if (__resolve_symbol(btf, type_id))
98 			break;
99 	}
100 
101 	btf__free(btf);
102 	return 0;
103 }
104 
105 int test_resolve_btfids(void)
106 {
107 	__u32 *test_list, *test_lists[] = { test_list_local, test_list_global };
108 	unsigned int i, j;
109 	int ret = 0;
110 
111 	if (resolve_symbols())
112 		return -1;
113 
114 	/* Check BTF_ID_LIST(test_list_local) and
115 	 * BTF_ID_LIST_GLOBAL(test_list_global) IDs
116 	 */
117 	for (j = 0; j < ARRAY_SIZE(test_lists); j++) {
118 		test_list = test_lists[j];
119 		for (i = 0; i < ARRAY_SIZE(test_symbols) && !ret; i++) {
120 			ret = CHECK(test_list[i] != test_symbols[i].id,
121 				    "id_check",
122 				    "wrong ID for %s (%d != %d)\n",
123 				    test_symbols[i].name,
124 				    test_list[i], test_symbols[i].id);
125 		}
126 	}
127 
128 	return ret;
129 }
130