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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <test_progs.h>
   3 #include <sys/mman.h>
   4 #include "test_mmap.skel.h"
   5
   6 struct map_data {
   7         __u64 val[512 * 4];
   8 };
   9
  10 static size_t roundup_page(size_t sz)
  11 {
  12         long page_size = sysconf(_SC_PAGE_SIZE);
  13         return (sz + page_size - 1) / page_size * page_size;
  14 }
  15
  16 void test_mmap(void)
  17 {
  18         const size_t bss_sz = roundup_page(sizeof(struct test_mmap__bss));
  19         const size_t map_sz = roundup_page(sizeof(struct map_data));
  20         const int zero = 0, one = 1, two = 2, far = 1500;
  21         const long page_size = sysconf(_SC_PAGE_SIZE);
  22         int err, duration = 0, i, data_map_fd;
  23         struct bpf_map *data_map, *bss_map;
  24         void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp1, *tmp2;
  25         struct test_mmap__bss *bss_data;
  26         struct map_data *map_data;
  27         struct test_mmap *skel;
  28         __u64 val = 0;
  29
  30
  31         skel = test_mmap__open_and_load();
  32         if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n"))
  33                 return;
  34
  35         bss_map = skel->maps.bss;
  36         data_map = skel->maps.data_map;
  37         data_map_fd = bpf_map__fd(data_map);
  38
  39         bss_mmaped = mmap(NULL, bss_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
  40                           bpf_map__fd(bss_map), 0);
  41         if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap",
  42                   ".bss mmap failed: %d\n", errno)) {
  43                 bss_mmaped = NULL;
  44                 goto cleanup;
  45         }
  46         /* map as R/W first */
  47         map_mmaped = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
  48                           data_map_fd, 0);
  49         if (CHECK(map_mmaped == MAP_FAILED, "data_mmap",
  50                   "data_map mmap failed: %d\n", errno)) {
  51                 map_mmaped = NULL;
  52                 goto cleanup;
  53         }
  54
  55         bss_data = bss_mmaped;
  56         map_data = map_mmaped;
  57
  58         CHECK_FAIL(bss_data->in_val);
  59         CHECK_FAIL(bss_data->out_val);
  60         CHECK_FAIL(skel->bss->in_val);
  61         CHECK_FAIL(skel->bss->out_val);
  62         CHECK_FAIL(map_data->val[0]);
  63         CHECK_FAIL(map_data->val[1]);
  64         CHECK_FAIL(map_data->val[2]);
  65         CHECK_FAIL(map_data->val[far]);
  66
  67         err = test_mmap__attach(skel);
  68         if (CHECK(err, "attach_raw_tp", "err %d\n", err))
  69                 goto cleanup;
  70
  71         bss_data->in_val = 123;
  72         val = 111;
  73         CHECK_FAIL(bpf_map_update_elem(data_map_fd, &zero, &val, 0));
  74
  75         usleep(1);
  76
  77         CHECK_FAIL(bss_data->in_val != 123);
  78         CHECK_FAIL(bss_data->out_val != 123);
  79         CHECK_FAIL(skel->bss->in_val != 123);
  80         CHECK_FAIL(skel->bss->out_val != 123);
  81         CHECK_FAIL(map_data->val[0] != 111);
  82         CHECK_FAIL(map_data->val[1] != 222);
  83         CHECK_FAIL(map_data->val[2] != 123);
  84         CHECK_FAIL(map_data->val[far] != 3 * 123);
  85
  86         CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &zero, &val));
  87         CHECK_FAIL(val != 111);
  88         CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &one, &val));
  89         CHECK_FAIL(val != 222);
  90         CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &two, &val));
  91         CHECK_FAIL(val != 123);
  92         CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &far, &val));
  93         CHECK_FAIL(val != 3 * 123);
  94
  95         /* data_map freeze should fail due to R/W mmap() */
  96         err = bpf_map_freeze(data_map_fd);
  97         if (CHECK(!err || errno != EBUSY, "no_freeze",
  98                   "data_map freeze succeeded: err=%d, errno=%d\n", err, errno))
  99                 goto cleanup;
 100
 101         /* unmap R/W mapping */
 102         err = munmap(map_mmaped, map_sz);
 103         map_mmaped = NULL;
 104         if (CHECK(err, "data_map_munmap", "data_map munmap failed: %d\n", errno))
 105                 goto cleanup;
 106
 107         /* re-map as R/O now */
 108         map_mmaped = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0);
 109         if (CHECK(map_mmaped == MAP_FAILED, "data_mmap",
 110                   "data_map R/O mmap failed: %d\n", errno)) {
 111                 map_mmaped = NULL;
 112                 goto cleanup;
 113         }
 114         map_data = map_mmaped;
 115
 116         /* map/unmap in a loop to test ref counting */
 117         for (i = 0; i < 10; i++) {
 118                 int flags = i % 2 ? PROT_READ : PROT_WRITE;
 119                 void *p;
 120
 121                 p = mmap(NULL, map_sz, flags, MAP_SHARED, data_map_fd, 0);
 122                 if (CHECK_FAIL(p == MAP_FAILED))
 123                         goto cleanup;
 124                 err = munmap(p, map_sz);
 125                 if (CHECK_FAIL(err))
 126                         goto cleanup;
 127         }
 128
 129         /* data_map freeze should now succeed due to no R/W mapping */
 130         err = bpf_map_freeze(data_map_fd);
 131         if (CHECK(err, "freeze", "data_map freeze failed: err=%d, errno=%d\n",
 132                   err, errno))
 133                 goto cleanup;
 134
 135         /* mapping as R/W now should fail */
 136         tmp1 = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED,
 137                     data_map_fd, 0);
 138         if (CHECK(tmp1 != MAP_FAILED, "data_mmap", "mmap succeeded\n")) {
 139                 munmap(tmp1, map_sz);
 140                 goto cleanup;
 141         }
 142
 143         bss_data->in_val = 321;
 144         usleep(1);
 145         CHECK_FAIL(bss_data->in_val != 321);
 146         CHECK_FAIL(bss_data->out_val != 321);
 147         CHECK_FAIL(skel->bss->in_val != 321);
 148         CHECK_FAIL(skel->bss->out_val != 321);
 149         CHECK_FAIL(map_data->val[0] != 111);
 150         CHECK_FAIL(map_data->val[1] != 222);
 151         CHECK_FAIL(map_data->val[2] != 321);
 152         CHECK_FAIL(map_data->val[far] != 3 * 321);
 153
 154         /* check some more advanced mmap() manipulations */
 155
 156         /* map all but last page: pages 1-3 mapped */
 157         tmp1 = mmap(NULL, 3 * page_size, PROT_READ, MAP_SHARED,
 158                           data_map_fd, 0);
 159         if (CHECK(tmp1 == MAP_FAILED, "adv_mmap1", "errno %d\n", errno))
 160                 goto cleanup;
 161
 162         /* unmap second page: pages 1, 3 mapped */
 163         err = munmap(tmp1 + page_size, page_size);
 164         if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) {
 165                 munmap(tmp1, map_sz);
 166                 goto cleanup;
 167         }
 168
 169         /* map page 2 back */
 170         tmp2 = mmap(tmp1 + page_size, page_size, PROT_READ,
 171                     MAP_SHARED | MAP_FIXED, data_map_fd, 0);
 172         if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) {
 173                 munmap(tmp1, page_size);
 174                 munmap(tmp1 + 2*page_size, page_size);
 175                 goto cleanup;
 176         }
 177         CHECK(tmp1 + page_size != tmp2, "adv_mmap4",
 178               "tmp1: %p, tmp2: %p\n", tmp1, tmp2);
 179
 180         /* re-map all 4 pages */
 181         tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,
 182                     data_map_fd, 0);
 183         if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) {
 184                 munmap(tmp1, 3 * page_size); /* unmap page 1 */
 185                 goto cleanup;
 186         }
 187         CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2);
 188
 189         map_data = tmp2;
 190         CHECK_FAIL(bss_data->in_val != 321);
 191         CHECK_FAIL(bss_data->out_val != 321);
 192         CHECK_FAIL(skel->bss->in_val != 321);
 193         CHECK_FAIL(skel->bss->out_val != 321);
 194         CHECK_FAIL(map_data->val[0] != 111);
 195         CHECK_FAIL(map_data->val[1] != 222);
 196         CHECK_FAIL(map_data->val[2] != 321);
 197         CHECK_FAIL(map_data->val[far] != 3 * 321);
 198
 199         munmap(tmp2, 4 * page_size);
 200 cleanup:
 201         if (bss_mmaped)
 202                 CHECK_FAIL(munmap(bss_mmaped, bss_sz));
 203         if (map_mmaped)
 204                 CHECK_FAIL(munmap(map_mmaped, map_sz));
 205         test_mmap__destroy(skel);
 206 }