LXR linux/tools/testing/selftests/bpf/prog

   1// SPDX-License-Identifier: GPL-2.0
   2#include <test_progs.h>
   3#include <sys/mman.h>
   4#include "test_mmap.skel.h"
   5
   6struct map_data {
   7        __u64 val[512 * 4];
   8};
   9
  10static 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
  16void 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);
 200cleanup:
 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}
 207