305 lines · c
1// SPDX-License-Identifier: GPL-2.02#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, data_map_id, tmp_fd, rdmap_fd;23 struct bpf_map *data_map, *bss_map;24 void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp0, *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();33 if (CHECK(!skel, "skel_open", "skeleton open failed\n"))34 return;35 36 err = bpf_map__set_max_entries(skel->maps.rdonly_map, page_size);37 if (CHECK(err != 0, "bpf_map__set_max_entries", "bpf_map__set_max_entries failed\n"))38 goto cleanup;39 40 /* at least 4 pages of data */41 err = bpf_map__set_max_entries(skel->maps.data_map,42 4 * (page_size / sizeof(u64)));43 if (CHECK(err != 0, "bpf_map__set_max_entries", "bpf_map__set_max_entries failed\n"))44 goto cleanup;45 46 err = test_mmap__load(skel);47 if (CHECK(err != 0, "skel_load", "skeleton load failed\n"))48 goto cleanup;49 50 bss_map = skel->maps.bss;51 data_map = skel->maps.data_map;52 data_map_fd = bpf_map__fd(data_map);53 54 rdmap_fd = bpf_map__fd(skel->maps.rdonly_map);55 tmp1 = mmap(NULL, page_size, PROT_READ | PROT_WRITE, MAP_SHARED, rdmap_fd, 0);56 if (CHECK(tmp1 != MAP_FAILED, "rdonly_write_mmap", "unexpected success\n")) {57 munmap(tmp1, page_size);58 goto cleanup;59 }60 /* now double-check if it's mmap()'able at all */61 tmp1 = mmap(NULL, page_size, PROT_READ, MAP_SHARED, rdmap_fd, 0);62 if (CHECK(tmp1 == MAP_FAILED, "rdonly_read_mmap", "failed: %d\n", errno))63 goto cleanup;64 65 /* get map's ID */66 memset(&map_info, 0, map_info_sz);67 err = bpf_map_get_info_by_fd(data_map_fd, &map_info, &map_info_sz);68 if (CHECK(err, "map_get_info", "failed %d\n", errno))69 goto cleanup;70 data_map_id = map_info.id;71 72 /* mmap BSS map */73 bss_mmaped = mmap(NULL, bss_sz, PROT_READ | PROT_WRITE, MAP_SHARED,74 bpf_map__fd(bss_map), 0);75 if (CHECK(bss_mmaped == MAP_FAILED, "bss_mmap",76 ".bss mmap failed: %d\n", errno)) {77 bss_mmaped = NULL;78 goto cleanup;79 }80 /* map as R/W first */81 map_mmaped = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED,82 data_map_fd, 0);83 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap",84 "data_map mmap failed: %d\n", errno)) {85 map_mmaped = NULL;86 goto cleanup;87 }88 89 bss_data = bss_mmaped;90 map_data = map_mmaped;91 92 CHECK_FAIL(bss_data->in_val);93 CHECK_FAIL(bss_data->out_val);94 CHECK_FAIL(skel->bss->in_val);95 CHECK_FAIL(skel->bss->out_val);96 CHECK_FAIL(map_data->val[0]);97 CHECK_FAIL(map_data->val[1]);98 CHECK_FAIL(map_data->val[2]);99 CHECK_FAIL(map_data->val[far]);100 101 err = test_mmap__attach(skel);102 if (CHECK(err, "attach_raw_tp", "err %d\n", err))103 goto cleanup;104 105 bss_data->in_val = 123;106 val = 111;107 CHECK_FAIL(bpf_map_update_elem(data_map_fd, &zero, &val, 0));108 109 usleep(1);110 111 CHECK_FAIL(bss_data->in_val != 123);112 CHECK_FAIL(bss_data->out_val != 123);113 CHECK_FAIL(skel->bss->in_val != 123);114 CHECK_FAIL(skel->bss->out_val != 123);115 CHECK_FAIL(map_data->val[0] != 111);116 CHECK_FAIL(map_data->val[1] != 222);117 CHECK_FAIL(map_data->val[2] != 123);118 CHECK_FAIL(map_data->val[far] != 3 * 123);119 120 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &zero, &val));121 CHECK_FAIL(val != 111);122 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &one, &val));123 CHECK_FAIL(val != 222);124 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &two, &val));125 CHECK_FAIL(val != 123);126 CHECK_FAIL(bpf_map_lookup_elem(data_map_fd, &far, &val));127 CHECK_FAIL(val != 3 * 123);128 129 /* data_map freeze should fail due to R/W mmap() */130 err = bpf_map_freeze(data_map_fd);131 if (CHECK(!err || errno != EBUSY, "no_freeze",132 "data_map freeze succeeded: err=%d, errno=%d\n", err, errno))133 goto cleanup;134 135 err = mprotect(map_mmaped, map_sz, PROT_READ);136 if (CHECK(err, "mprotect_ro", "mprotect to r/o failed %d\n", errno))137 goto cleanup;138 139 /* unmap R/W mapping */140 err = munmap(map_mmaped, map_sz);141 map_mmaped = NULL;142 if (CHECK(err, "data_map_munmap", "data_map munmap failed: %d\n", errno))143 goto cleanup;144 145 /* re-map as R/O now */146 map_mmaped = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0);147 if (CHECK(map_mmaped == MAP_FAILED, "data_mmap",148 "data_map R/O mmap failed: %d\n", errno)) {149 map_mmaped = NULL;150 goto cleanup;151 }152 err = mprotect(map_mmaped, map_sz, PROT_WRITE);153 if (CHECK(!err, "mprotect_wr", "mprotect() succeeded unexpectedly!\n"))154 goto cleanup;155 err = mprotect(map_mmaped, map_sz, PROT_EXEC);156 if (CHECK(!err, "mprotect_ex", "mprotect() succeeded unexpectedly!\n"))157 goto cleanup;158 map_data = map_mmaped;159 160 /* map/unmap in a loop to test ref counting */161 for (i = 0; i < 10; i++) {162 int flags = i % 2 ? PROT_READ : PROT_WRITE;163 void *p;164 165 p = mmap(NULL, map_sz, flags, MAP_SHARED, data_map_fd, 0);166 if (CHECK_FAIL(p == MAP_FAILED))167 goto cleanup;168 err = munmap(p, map_sz);169 if (CHECK_FAIL(err))170 goto cleanup;171 }172 173 /* data_map freeze should now succeed due to no R/W mapping */174 err = bpf_map_freeze(data_map_fd);175 if (CHECK(err, "freeze", "data_map freeze failed: err=%d, errno=%d\n",176 err, errno))177 goto cleanup;178 179 /* mapping as R/W now should fail */180 tmp1 = mmap(NULL, map_sz, PROT_READ | PROT_WRITE, MAP_SHARED,181 data_map_fd, 0);182 if (CHECK(tmp1 != MAP_FAILED, "data_mmap", "mmap succeeded\n")) {183 munmap(tmp1, map_sz);184 goto cleanup;185 }186 187 bss_data->in_val = 321;188 usleep(1);189 CHECK_FAIL(bss_data->in_val != 321);190 CHECK_FAIL(bss_data->out_val != 321);191 CHECK_FAIL(skel->bss->in_val != 321);192 CHECK_FAIL(skel->bss->out_val != 321);193 CHECK_FAIL(map_data->val[0] != 111);194 CHECK_FAIL(map_data->val[1] != 222);195 CHECK_FAIL(map_data->val[2] != 321);196 CHECK_FAIL(map_data->val[far] != 3 * 321);197 198 /* check some more advanced mmap() manipulations */199 200 tmp0 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_ANONYMOUS,201 -1, 0);202 if (CHECK(tmp0 == MAP_FAILED, "adv_mmap0", "errno %d\n", errno))203 goto cleanup;204 205 /* map all but last page: pages 1-3 mapped */206 tmp1 = mmap(tmp0, 3 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,207 data_map_fd, 0);208 if (CHECK(tmp0 != tmp1, "adv_mmap1", "tmp0: %p, tmp1: %p\n", tmp0, tmp1)) {209 munmap(tmp0, 4 * page_size);210 goto cleanup;211 }212 213 /* unmap second page: pages 1, 3 mapped */214 err = munmap(tmp1 + page_size, page_size);215 if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) {216 munmap(tmp1, 4 * page_size);217 goto cleanup;218 }219 220 /* map page 2 back */221 tmp2 = mmap(tmp1 + page_size, page_size, PROT_READ,222 MAP_SHARED | MAP_FIXED, data_map_fd, 0);223 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) {224 munmap(tmp1, page_size);225 munmap(tmp1 + 2*page_size, 2 * page_size);226 goto cleanup;227 }228 CHECK(tmp1 + page_size != tmp2, "adv_mmap4",229 "tmp1: %p, tmp2: %p\n", tmp1, tmp2);230 231 /* re-map all 4 pages */232 tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,233 data_map_fd, 0);234 if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) {235 munmap(tmp1, 4 * page_size); /* unmap page 1 */236 goto cleanup;237 }238 CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2);239 240 map_data = tmp2;241 CHECK_FAIL(bss_data->in_val != 321);242 CHECK_FAIL(bss_data->out_val != 321);243 CHECK_FAIL(skel->bss->in_val != 321);244 CHECK_FAIL(skel->bss->out_val != 321);245 CHECK_FAIL(map_data->val[0] != 111);246 CHECK_FAIL(map_data->val[1] != 222);247 CHECK_FAIL(map_data->val[2] != 321);248 CHECK_FAIL(map_data->val[far] != 3 * 321);249 250 munmap(tmp2, 4 * page_size);251 252 /* map all 4 pages, but with pg_off=1 page, should fail */253 tmp1 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED,254 data_map_fd, page_size /* initial page shift */);255 if (CHECK(tmp1 != MAP_FAILED, "adv_mmap7", "unexpected success")) {256 munmap(tmp1, 4 * page_size);257 goto cleanup;258 }259 260 tmp1 = mmap(NULL, map_sz, PROT_READ, MAP_SHARED, data_map_fd, 0);261 if (CHECK(tmp1 == MAP_FAILED, "last_mmap", "failed %d\n", errno))262 goto cleanup;263 264 test_mmap__destroy(skel);265 skel = NULL;266 CHECK_FAIL(munmap(bss_mmaped, bss_sz));267 bss_mmaped = NULL;268 CHECK_FAIL(munmap(map_mmaped, map_sz));269 map_mmaped = NULL;270 271 /* map should be still held by active mmap */272 tmp_fd = bpf_map_get_fd_by_id(data_map_id);273 if (CHECK(tmp_fd < 0, "get_map_by_id", "failed %d\n", errno)) {274 munmap(tmp1, map_sz);275 goto cleanup;276 }277 close(tmp_fd);278 279 /* this should release data map finally */280 munmap(tmp1, map_sz);281 282 /* we need to wait for RCU grace period */283 for (i = 0; i < 10000; i++) {284 __u32 id = data_map_id - 1;285 if (bpf_map_get_next_id(id, &id) || id > data_map_id)286 break;287 usleep(1);288 }289 290 /* should fail to get map FD by non-existing ID */291 tmp_fd = bpf_map_get_fd_by_id(data_map_id);292 if (CHECK(tmp_fd >= 0, "get_map_by_id_after",293 "unexpectedly succeeded %d\n", tmp_fd)) {294 close(tmp_fd);295 goto cleanup;296 }297 298cleanup:299 if (bss_mmaped)300 CHECK_FAIL(munmap(bss_mmaped, bss_sz));301 if (map_mmaped)302 CHECK_FAIL(munmap(map_mmaped, map_sz));303 test_mmap__destroy(skel);304}305