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 BTF_SET_START(test_set)
51 BTF_ID(typedef, S)
52 BTF_ID(typedef, T)
53 BTF_ID(typedef, U)
54 BTF_ID(struct,  S)
55 BTF_ID(union,   U)
56 BTF_ID(func,    func)
57 BTF_SET_END(test_set)
58 
59 static int
60 __resolve_symbol(struct btf *btf, int type_id)
61 {
62 	const struct btf_type *type;
63 	const char *str;
64 	unsigned int i;
65 
66 	type = btf__type_by_id(btf, type_id);
67 	if (!type) {
68 		PRINT_FAIL("Failed to get type for ID %d\n", type_id);
69 		return -1;
70 	}
71 
72 	for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
73 		if (test_symbols[i].id != -1)
74 			continue;
75 
76 		if (BTF_INFO_KIND(type->info) != test_symbols[i].type)
77 			continue;
78 
79 		str = btf__name_by_offset(btf, type->name_off);
80 		if (!str) {
81 			PRINT_FAIL("Failed to get name for BTF ID %d\n", type_id);
82 			return -1;
83 		}
84 
85 		if (!strcmp(str, test_symbols[i].name))
86 			test_symbols[i].id = type_id;
87 	}
88 
89 	return 0;
90 }
91 
92 static int resolve_symbols(void)
93 {
94 	struct btf *btf;
95 	int type_id;
96 	__u32 nr;
97 
98 	btf = btf__parse_elf("btf_data.o", NULL);
99 	if (CHECK(libbpf_get_error(btf), "resolve",
100 		  "Failed to load BTF from btf_data.o\n"))
101 		return -1;
102 
103 	nr = btf__get_nr_types(btf);
104 
105 	for (type_id = 1; type_id <= nr; type_id++) {
106 		if (__resolve_symbol(btf, type_id))
107 			break;
108 	}
109 
110 	btf__free(btf);
111 	return 0;
112 }
113 
114 int test_resolve_btfids(void)
115 {
116 	__u32 *test_list, *test_lists[] = { test_list_local, test_list_global };
117 	unsigned int i, j;
118 	int ret = 0;
119 
120 	if (resolve_symbols())
121 		return -1;
122 
123 	/* Check BTF_ID_LIST(test_list_local) and
124 	 * BTF_ID_LIST_GLOBAL(test_list_global) IDs
125 	 */
126 	for (j = 0; j < ARRAY_SIZE(test_lists); j++) {
127 		test_list = test_lists[j];
128 		for (i = 0; i < ARRAY_SIZE(test_symbols); i++) {
129 			ret = CHECK(test_list[i] != test_symbols[i].id,
130 				    "id_check",
131 				    "wrong ID for %s (%d != %d)\n",
132 				    test_symbols[i].name,
133 				    test_list[i], test_symbols[i].id);
134 			if (ret)
135 				return ret;
136 		}
137 	}
138 
139 	/* Check BTF_SET_START(test_set) IDs */
140 	for (i = 0; i < test_set.cnt; i++) {
141 		bool found = false;
142 
143 		for (j = 0; j < ARRAY_SIZE(test_symbols); j++) {
144 			if (test_symbols[j].id != test_set.ids[i])
145 				continue;
146 			found = true;
147 			break;
148 		}
149 
150 		ret = CHECK(!found, "id_check",
151 			    "ID %d not found in test_symbols\n",
152 			    test_set.ids[i]);
153 		if (ret)
154 			break;
155 
156 		if (i > 0) {
157 			ret = CHECK(test_set.ids[i - 1] > test_set.ids[i],
158 				    "sort_check",
159 				    "test_set is not sorted\n");
160 			if (ret)
161 				break;
162 		}
163 	}
164 
165 	return ret;
166 }
167