tools/testing/selftests/bpf/prog_tests/resolve_btfids.c

   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 }