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, data_map_id, tmp_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 bpf_map_info map_info; 27 __u32 map_info_sz = sizeof(map_info); 28 struct map_data *map_data; 29 struct test_mmap *skel; 30 __u64 val = 0; 31 32 skel = test_mmap__open_and_load(); 33 if (CHECK(!skel, "skel_open_and_load", "skeleton open/load failed\n")) 34 return; 35 36 bss_map = skel->maps.bss; 37 data_map = skel->maps.data_map; 38 data_map_fd = bpf_map__fd(data_map); 39 40 /* get map's ID */ 41 memset(&map_info, 0, map_info_sz); 42 err = bpf_obj_get_info_by_fd(data_map_fd, &map_info, &map_info_sz); 43 if (CHECK(err, "map_get_info", "failed %d\n", errno)) 44 goto cleanup; 45 data_map_id = map_info.id; 46 47 /* mmap BSS map */ 48 bss_mmaped = mmap(NULL, bss_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 49 bpf_map__fd(bss_map), 0); 50 if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap", 51 ".bss mmap failed: %d\n", errno)) { 52 bss_mmaped = NULL; 53 goto cleanup; 54 } 55 /* map as R/W first */ 56 map_mmaped = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 57 data_map_fd, 0); 58 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap", 59 "data_map mmap failed: %d\n", errno)) { 60 map_mmaped = NULL; 61 goto cleanup; 62 } 63 64 bss_data = bss_mmaped; 65 map_data = map_mmaped; 66 67 CHECK_FAIL(bss_data->in_val); 68 CHECK_FAIL(bss_data->out_val); 69 CHECK_FAIL(skel->bss->in_val); 70 CHECK_FAIL(skel->bss->out_val); 71 CHECK_FAIL(map_data->val[0]); 72 CHECK_FAIL(map_data->val[1]); 73 CHECK_FAIL(map_data->val[2]); 74 CHECK_FAIL(map_data->val[far]); 75 76 err = test_mmap__attach(skel); 77 if (CHECK(err, "attach_raw_tp", "err %d\n", err)) 78 goto cleanup; 79 80 bss_data->in_val = 123; 81 val = 111; 82 CHECK_FAIL(bpf_map_update_elem(data_map_fd, &zero, &val, 0)); 83 84 usleep(1); 85 86 CHECK_FAIL(bss_data->in_val != 123); 87 CHECK_FAIL(bss_data->out_val != 123); 88 CHECK_FAIL(skel->bss->in_val != 123); 89 CHECK_FAIL(skel->bss->out_val != 123); 90 CHECK_FAIL(map_data->val[0] != 111); 91 CHECK_FAIL(map_data->val[1] != 222); 92 CHECK_FAIL(map_data->val[2] != 123); 93 CHECK_FAIL(map_data->val[far] != 3 * 123); 94 95 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &zero, &val)); 96 CHECK_FAIL(val != 111); 97 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &one, &val)); 98 CHECK_FAIL(val != 222); 99 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &two, &val)); 100 CHECK_FAIL(val != 123); 101 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &far, &val)); 102 CHECK_FAIL(val != 3 * 123); 103 104 /* data_map freeze should fail due to R/W mmap() */ 105 err = bpf_map_freeze(data_map_fd); 106 if (CHECK(!err || errno != EBUSY, "no_freeze", 107 "data_map freeze succeeded: err=%d, errno=%d\n", err, errno)) 108 goto cleanup; 109 110 err = mprotect(map_mmaped, map_sz, PROT_READ); 111 if (CHECK(err, "mprotect_ro", "mprotect to r/o failed %d\n", errno)) 112 goto cleanup; 113 114 /* unmap R/W mapping */ 115 err = munmap(map_mmaped, map_sz); 116 map_mmaped = NULL; 117 if (CHECK(err, "data_map_munmap", "data_map munmap failed: %d\n", errno)) 118 goto cleanup; 119 120 /* re-map as R/O now */ 121 map_mmaped = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0); 122 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap", 123 "data_map R/O mmap failed: %d\n", errno)) { 124 map_mmaped = NULL; 125 goto cleanup; 126 } 127 err = mprotect(map_mmaped, map_sz, PROT_WRITE); 128 if (CHECK(!err, "mprotect_wr", "mprotect() succeeded unexpectedly!\n")) 129 goto cleanup; 130 err = mprotect(map_mmaped, map_sz, PROT_EXEC); 131 if (CHECK(!err, "mprotect_ex", "mprotect() succeeded unexpectedly!\n")) 132 goto cleanup; 133 map_data = map_mmaped; 134 135 /* map/unmap in a loop to test ref counting */ 136 for (i = 0; i < 10; i++) { 137 int flags = i % 2 ? PROT_READ : PROT_WRITE; 138 void *p; 139 140 p = mmap(NULL, map_sz, flags, MAP_SHARED, data_map_fd, 0); 141 if (CHECK_FAIL(p == MAP_FAILED)) 142 goto cleanup; 143 err = munmap(p, map_sz); 144 if (CHECK_FAIL(err)) 145 goto cleanup; 146 } 147 148 /* data_map freeze should now succeed due to no R/W mapping */ 149 err = bpf_map_freeze(data_map_fd); 150 if (CHECK(err, "freeze", "data_map freeze failed: err=%d, errno=%d\n", 151 err, errno)) 152 goto cleanup; 153 154 /* mapping as R/W now should fail */ 155 tmp1 = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED, 156 data_map_fd, 0); 157 if (CHECK(tmp1 != MAP_FAILED, "data_mmap", "mmap succeeded\n")) { 158 munmap(tmp1, map_sz); 159 goto cleanup; 160 } 161 162 bss_data->in_val = 321; 163 usleep(1); 164 CHECK_FAIL(bss_data->in_val != 321); 165 CHECK_FAIL(bss_data->out_val != 321); 166 CHECK_FAIL(skel->bss->in_val != 321); 167 CHECK_FAIL(skel->bss->out_val != 321); 168 CHECK_FAIL(map_data->val[0] != 111); 169 CHECK_FAIL(map_data->val[1] != 222); 170 CHECK_FAIL(map_data->val[2] != 321); 171 CHECK_FAIL(map_data->val[far] != 3 * 321); 172 173 /* check some more advanced mmap() manipulations */ 174 175 /* map all but last page: pages 1-3 mapped */ 176 tmp1 = mmap(NULL, 3 * page_size, PROT_READ, MAP_SHARED, 177 data_map_fd, 0); 178 if (CHECK(tmp1 == MAP_FAILED, "adv_mmap1", "errno %d\n", errno)) 179 goto cleanup; 180 181 /* unmap second page: pages 1, 3 mapped */ 182 err = munmap(tmp1 + page_size, page_size); 183 if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) { 184 munmap(tmp1, map_sz); 185 goto cleanup; 186 } 187 188 /* map page 2 back */ 189 tmp2 = mmap(tmp1 + page_size, page_size, PROT_READ, 190 MAP_SHARED | MAP_FIXED, data_map_fd, 0); 191 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) { 192 munmap(tmp1, page_size); 193 munmap(tmp1 + 2*page_size, page_size); 194 goto cleanup; 195 } 196 CHECK(tmp1 + page_size != tmp2, "adv_mmap4", 197 "tmp1: %p, tmp2: %p\n", tmp1, tmp2); 198 199 /* re-map all 4 pages */ 200 tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, 201 data_map_fd, 0); 202 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) { 203 munmap(tmp1, 3 * page_size); /* unmap page 1 */ 204 goto cleanup; 205 } 206 CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2); 207 208 map_data = tmp2; 209 CHECK_FAIL(bss_data->in_val != 321); 210 CHECK_FAIL(bss_data->out_val != 321); 211 CHECK_FAIL(skel->bss->in_val != 321); 212 CHECK_FAIL(skel->bss->out_val != 321); 213 CHECK_FAIL(map_data->val[0] != 111); 214 CHECK_FAIL(map_data->val[1] != 222); 215 CHECK_FAIL(map_data->val[2] != 321); 216 CHECK_FAIL(map_data->val[far] != 3 * 321); 217 218 munmap(tmp2, 4 * page_size); 219 220 tmp1 = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0); 221 if (CHECK(tmp1 == MAP_FAILED, "last_mmap", "failed %d\n", errno)) 222 goto cleanup; 223 224 test_mmap__destroy(skel); 225 skel = NULL; 226 CHECK_FAIL(munmap(bss_mmaped, bss_sz)); 227 bss_mmaped = NULL; 228 CHECK_FAIL(munmap(map_mmaped, map_sz)); 229 map_mmaped = NULL; 230 231 /* map should be still held by active mmap */ 232 tmp_fd = bpf_map_get_fd_by_id(data_map_id); 233 if (CHECK(tmp_fd < 0, "get_map_by_id", "failed %d\n", errno)) { 234 munmap(tmp1, map_sz); 235 goto cleanup; 236 } 237 close(tmp_fd); 238 239 /* this should release data map finally */ 240 munmap(tmp1, map_sz); 241 242 /* we need to wait for RCU grace period */ 243 for (i = 0; i < 10000; i++) { 244 __u32 id = data_map_id - 1; 245 if (bpf_map_get_next_id(id, &id) || id > data_map_id) 246 break; 247 usleep(1); 248 } 249 250 /* should fail to get map FD by non-existing ID */ 251 tmp_fd = bpf_map_get_fd_by_id(data_map_id); 252 if (CHECK(tmp_fd >= 0, "get_map_by_id_after", 253 "unexpectedly succeeded %d\n", tmp_fd)) { 254 close(tmp_fd); 255 goto cleanup; 256 } 257 258 cleanup: 259 if (bss_mmaped) 260 CHECK_FAIL(munmap(bss_mmaped, bss_sz)); 261 if (map_mmaped) 262 CHECK_FAIL(munmap(map_mmaped, map_sz)); 263 test_mmap__destroy(skel); 264 } 265