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.bpf.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}