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        if (CHECK_FAIL(!obj))
  16                return;
  17
  18        map = bpf_object__find_map_by_name(obj, "test_glo.rodata");
  19        if (CHECK_FAIL(!map || !bpf_map__is_internal(map)))
  20                goto out;
  21
  22        sz = bpf_map__def(map)->value_size;
  23        newval = malloc(sz);
  24        if (CHECK_FAIL(!newval))
  25                goto out;
  26
  27        memset(newval, 0, sz);
  28        /* wrong size, should fail */
  29        err = bpf_map__set_initial_value(map, newval, sz - 1);
  30        if (CHECK(!err, "reject set initial value wrong size", "err %d\n", err))
  31                goto out;
  32
  33        err = bpf_map__set_initial_value(map, newval, sz);
  34        if (CHECK(err, "set initial value", "err %d\n", err))
  35                goto out;
  36
  37        err = bpf_object__load(obj);
  38        if (CHECK_FAIL(err))
  39                goto out;
  40
  41        map_fd = bpf_map__fd(map);
  42        if (CHECK_FAIL(map_fd < 0))
  43                goto out;
  44
  45        buff = malloc(sz);
  46        if (buff)
  47                err = bpf_map_lookup_elem(map_fd, &zero, buff);
  48        if (CHECK(!buff || err || memcmp(buff, newval, sz),
  49                  "compare .rodata map data override",
  50                  "err %d errno %d\n", err, errno))
  51                goto out;
  52
  53        memset(newval, 1, sz);
  54        /* object loaded - should fail */
  55        err = bpf_map__set_initial_value(map, newval, sz);
  56        CHECK(!err, "reject set initial value after load", "err %d\n", err);
  57out:
  58        free(buff);
  59        free(newval);
  60        bpf_object__close(obj);
  61}
  62