LXR linux/tools/testing/selftests/bpf/prog_tests/resolve

   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)
  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.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__get_nr_types(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
 120int 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 -1;
 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 ret;
 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 -1;
 165                }
 166        }
 167
 168        return ret;
 169}
 170