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

   1// SPDX-License-Identifier: GPL-2.0
   2#include <test_progs.h>
   3
   4void test_global_data_init(void)
   5{
   6        const char *file = "./test_global_data.o";
   7        int err = -ENOMEM, map_fd, zero = 0;
   8        __u8 *buff = NULL, *newval = NULL;
   9        struct bpf_object *obj;
  10        struct bpf_map *map;
  11        __u32 duration = 0;
  12        size_t sz;
  13
  14        obj = bpf_object__open_file(file, NULL);
  15        err = libbpf_get_error(obj);
  16        if (CHECK_FAIL(err))
  17                return;
  18
  19        map = bpf_object__find_map_by_name(obj, "test_glo.rodata");
  20        if (CHECK_FAIL(!map || !bpf_map__is_internal(map)))
  21                goto out;
  22
  23        sz = bpf_map__def(map)->value_size;
  24        newval = malloc(sz);
  25        if (CHECK_FAIL(!newval))
  26                goto out;
  27
  28        memset(newval, 0, sz);
  29        /* wrong size, should fail */
  30        err = bpf_map__set_initial_value(map, newval, sz - 1);
  31        if (CHECK(!err, "reject set initial value wrong size", "err %d\n", err))
  32                goto out;
  33
  34        err = bpf_map__set_initial_value(map, newval, sz);
  35        if (CHECK(err, "set initial value", "err %d\n", err))
  36                goto out;
  37
  38        err = bpf_object__load(obj);
  39        if (CHECK_FAIL(err))
  40                goto out;
  41
  42        map_fd = bpf_map__fd(map);
  43        if (CHECK_FAIL(map_fd < 0))
  44                goto out;
  45
  46        buff = malloc(sz);
  47        if (buff)
  48                err = bpf_map_lookup_elem(map_fd, &zero, buff);
  49        if (CHECK(!buff || err || memcmp(buff, newval, sz),
  50                  "compare .rodata map data override",
  51                  "err %d errno %d\n", err, errno))
  52                goto out;
  53
  54        memset(newval, 1, sz);
  55        /* object loaded - should fail */
  56        err = bpf_map__set_initial_value(map, newval, sz);
  57        CHECK(!err, "reject set initial value after load", "err %d\n", err);
  58out:
  59        free(buff);
  60        free(newval);
  61        bpf_object__close(obj);
  62}
  63