1 // SPDX-License-Identifier: GPL-2.0 2 3 #include <test_progs.h> 4 5 #include <linux/btf.h> 6 #include <bpf/bpf.h> 7 8 #include "../test_btf.h" 9 10 static inline int new_map(void) 11 { 12 const char *name = NULL; 13 __u32 max_entries = 1; 14 __u32 value_size = 8; 15 __u32 key_size = 4; 16 17 return bpf_map_create(BPF_MAP_TYPE_ARRAY, name, 18 key_size, value_size, 19 max_entries, NULL); 20 } 21 22 static int new_btf(void) 23 { 24 struct btf_blob { 25 struct btf_header btf_hdr; 26 __u32 types[8]; 27 __u32 str; 28 } raw_btf = { 29 .btf_hdr = { 30 .magic = BTF_MAGIC, 31 .version = BTF_VERSION, 32 .hdr_len = sizeof(struct btf_header), 33 .type_len = sizeof(raw_btf.types), 34 .str_off = offsetof(struct btf_blob, str) - offsetof(struct btf_blob, types), 35 .str_len = sizeof(raw_btf.str), 36 }, 37 .types = { 38 /* long */ 39 BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 64, 8), /* [1] */ 40 /* unsigned long */ 41 BTF_TYPE_INT_ENC(0, 0, 0, 64, 8), /* [2] */ 42 }, 43 }; 44 45 return bpf_btf_load(&raw_btf, sizeof(raw_btf), NULL); 46 } 47 48 #define Close(FD) do { \ 49 if ((FD) >= 0) { \ 50 close(FD); \ 51 FD = -1; \ 52 } \ 53 } while(0) 54 55 static bool map_exists(__u32 id) 56 { 57 int fd; 58 59 fd = bpf_map_get_fd_by_id(id); 60 if (fd >= 0) { 61 close(fd); 62 return true; 63 } 64 return false; 65 } 66 67 static bool btf_exists(__u32 id) 68 { 69 int fd; 70 71 fd = bpf_btf_get_fd_by_id(id); 72 if (fd >= 0) { 73 close(fd); 74 return true; 75 } 76 return false; 77 } 78 79 static inline int bpf_prog_get_map_ids(int prog_fd, __u32 *nr_map_ids, __u32 *map_ids) 80 { 81 __u32 len = sizeof(struct bpf_prog_info); 82 struct bpf_prog_info info; 83 int err; 84 85 memset(&info, 0, len); 86 info.nr_map_ids = *nr_map_ids, 87 info.map_ids = ptr_to_u64(map_ids), 88 89 err = bpf_prog_get_info_by_fd(prog_fd, &info, &len); 90 if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd")) 91 return -1; 92 93 *nr_map_ids = info.nr_map_ids; 94 95 return 0; 96 } 97 98 static int __load_test_prog(int map_fd, const int *fd_array, int fd_array_cnt) 99 { 100 /* A trivial program which uses one map */ 101 struct bpf_insn insns[] = { 102 BPF_LD_MAP_FD(BPF_REG_1, map_fd), 103 BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), 104 BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), 105 BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -8), 106 BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), 107 BPF_MOV64_IMM(BPF_REG_0, 0), 108 BPF_EXIT_INSN(), 109 }; 110 LIBBPF_OPTS(bpf_prog_load_opts, opts); 111 112 opts.fd_array = fd_array; 113 opts.fd_array_cnt = fd_array_cnt; 114 115 return bpf_prog_load(BPF_PROG_TYPE_XDP, NULL, "GPL", insns, ARRAY_SIZE(insns), &opts); 116 } 117 118 static int load_test_prog(const int *fd_array, int fd_array_cnt) 119 { 120 int map_fd; 121 int ret; 122 123 map_fd = new_map(); 124 if (!ASSERT_GE(map_fd, 0, "new_map")) 125 return map_fd; 126 127 ret = __load_test_prog(map_fd, fd_array, fd_array_cnt); 128 close(map_fd); 129 return ret; 130 } 131 132 static bool check_expected_map_ids(int prog_fd, int expected, __u32 *map_ids, __u32 *nr_map_ids) 133 { 134 int err; 135 136 err = bpf_prog_get_map_ids(prog_fd, nr_map_ids, map_ids); 137 if (!ASSERT_OK(err, "bpf_prog_get_map_ids")) 138 return false; 139 if (!ASSERT_EQ(*nr_map_ids, expected, "unexpected nr_map_ids")) 140 return false; 141 142 return true; 143 } 144 145 /* 146 * Load a program, which uses one map. No fd_array maps are present. 147 * On return only one map is expected to be bound to prog. 148 */ 149 static void check_fd_array_cnt__no_fd_array(void) 150 { 151 __u32 map_ids[16]; 152 __u32 nr_map_ids; 153 int prog_fd = -1; 154 155 prog_fd = load_test_prog(NULL, 0); 156 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD")) 157 return; 158 nr_map_ids = ARRAY_SIZE(map_ids); 159 check_expected_map_ids(prog_fd, 1, map_ids, &nr_map_ids); 160 close(prog_fd); 161 } 162 163 /* 164 * Load a program, which uses one map, and pass two extra, non-equal, maps in 165 * fd_array with fd_array_cnt=2. On return three maps are expected to be bound 166 * to the program. 167 */ 168 static void check_fd_array_cnt__fd_array_ok(void) 169 { 170 int extra_fds[2] = { -1, -1 }; 171 __u32 map_ids[16]; 172 __u32 nr_map_ids; 173 int prog_fd = -1; 174 175 extra_fds[0] = new_map(); 176 if (!ASSERT_GE(extra_fds[0], 0, "new_map")) 177 goto cleanup; 178 extra_fds[1] = new_map(); 179 if (!ASSERT_GE(extra_fds[1], 0, "new_map")) 180 goto cleanup; 181 prog_fd = load_test_prog(extra_fds, 2); 182 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD")) 183 goto cleanup; 184 nr_map_ids = ARRAY_SIZE(map_ids); 185 if (!check_expected_map_ids(prog_fd, 3, map_ids, &nr_map_ids)) 186 goto cleanup; 187 188 /* maps should still exist when original file descriptors are closed */ 189 Close(extra_fds[0]); 190 Close(extra_fds[1]); 191 if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map_ids[0] should exist")) 192 goto cleanup; 193 if (!ASSERT_EQ(map_exists(map_ids[1]), true, "map_ids[1] should exist")) 194 goto cleanup; 195 196 /* some fds might be invalid, so ignore return codes */ 197 cleanup: 198 Close(extra_fds[1]); 199 Close(extra_fds[0]); 200 Close(prog_fd); 201 } 202 203 /* 204 * Load a program with a few extra maps duplicated in the fd_array. 205 * After the load maps should only be referenced once. 206 */ 207 static void check_fd_array_cnt__duplicated_maps(void) 208 { 209 int extra_fds[4] = { -1, -1, -1, -1 }; 210 __u32 map_ids[16]; 211 __u32 nr_map_ids; 212 int prog_fd = -1; 213 214 extra_fds[0] = extra_fds[2] = new_map(); 215 if (!ASSERT_GE(extra_fds[0], 0, "new_map")) 216 goto cleanup; 217 extra_fds[1] = extra_fds[3] = new_map(); 218 if (!ASSERT_GE(extra_fds[1], 0, "new_map")) 219 goto cleanup; 220 prog_fd = load_test_prog(extra_fds, 4); 221 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD")) 222 goto cleanup; 223 nr_map_ids = ARRAY_SIZE(map_ids); 224 if (!check_expected_map_ids(prog_fd, 3, map_ids, &nr_map_ids)) 225 goto cleanup; 226 227 /* maps should still exist when original file descriptors are closed */ 228 Close(extra_fds[0]); 229 Close(extra_fds[1]); 230 if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map should exist")) 231 goto cleanup; 232 if (!ASSERT_EQ(map_exists(map_ids[1]), true, "map should exist")) 233 goto cleanup; 234 235 /* some fds might be invalid, so ignore return codes */ 236 cleanup: 237 Close(extra_fds[1]); 238 Close(extra_fds[0]); 239 Close(prog_fd); 240 } 241 242 /* 243 * Check that if maps which are referenced by a program are 244 * passed in fd_array, then they will be referenced only once 245 */ 246 static void check_fd_array_cnt__referenced_maps_in_fd_array(void) 247 { 248 int extra_fds[1] = { -1 }; 249 __u32 map_ids[16]; 250 __u32 nr_map_ids; 251 int prog_fd = -1; 252 253 extra_fds[0] = new_map(); 254 if (!ASSERT_GE(extra_fds[0], 0, "new_map")) 255 goto cleanup; 256 prog_fd = __load_test_prog(extra_fds[0], extra_fds, 1); 257 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD")) 258 goto cleanup; 259 nr_map_ids = ARRAY_SIZE(map_ids); 260 if (!check_expected_map_ids(prog_fd, 1, map_ids, &nr_map_ids)) 261 goto cleanup; 262 263 /* map should still exist when original file descriptor is closed */ 264 Close(extra_fds[0]); 265 if (!ASSERT_EQ(map_exists(map_ids[0]), true, "map should exist")) 266 goto cleanup; 267 268 /* some fds might be invalid, so ignore return codes */ 269 cleanup: 270 Close(extra_fds[0]); 271 Close(prog_fd); 272 } 273 274 static int get_btf_id_by_fd(int btf_fd, __u32 *id) 275 { 276 struct bpf_btf_info info; 277 __u32 info_len = sizeof(info); 278 int err; 279 280 memset(&info, 0, info_len); 281 err = bpf_btf_get_info_by_fd(btf_fd, &info, &info_len); 282 if (err) 283 return err; 284 if (id) 285 *id = info.id; 286 return 0; 287 } 288 289 /* 290 * Check that fd_array operates properly for btfs. Namely, to check that 291 * passing a btf fd in fd_array increases its reference count, do the 292 * following: 293 * 1) Create a new btf, it's referenced only by a file descriptor, so refcnt=1 294 * 2) Load a BPF prog with fd_array[0] = btf_fd; now btf's refcnt=2 295 * 3) Close the btf_fd, now refcnt=1 296 * Wait and check that BTF stil exists. 297 */ 298 static void check_fd_array_cnt__referenced_btfs(void) 299 { 300 int extra_fds[1] = { -1 }; 301 int prog_fd = -1; 302 __u32 btf_id; 303 int tries; 304 int err; 305 306 extra_fds[0] = new_btf(); 307 if (!ASSERT_GE(extra_fds[0], 0, "new_btf")) 308 goto cleanup; 309 prog_fd = load_test_prog(extra_fds, 1); 310 if (!ASSERT_GE(prog_fd, 0, "BPF_PROG_LOAD")) 311 goto cleanup; 312 313 /* btf should still exist when original file descriptor is closed */ 314 err = get_btf_id_by_fd(extra_fds[0], &btf_id); 315 if (!ASSERT_GE(err, 0, "get_btf_id_by_fd")) 316 goto cleanup; 317 318 Close(extra_fds[0]); 319 320 if (!ASSERT_GE(kern_sync_rcu(), 0, "kern_sync_rcu 1")) 321 goto cleanup; 322 323 if (!ASSERT_EQ(btf_exists(btf_id), true, "btf should exist")) 324 goto cleanup; 325 326 Close(prog_fd); 327 328 /* The program is freed by a workqueue, so no reliable 329 * way to sync, so just wait a bit (max ~1 second). */ 330 for (tries = 100; tries >= 0; tries--) { 331 usleep(1000); 332 333 if (!btf_exists(btf_id)) 334 break; 335 336 if (tries) 337 continue; 338 339 PRINT_FAIL("btf should have been freed"); 340 } 341 342 /* some fds might be invalid, so ignore return codes */ 343 cleanup: 344 Close(extra_fds[0]); 345 Close(prog_fd); 346 } 347 348 /* 349 * Test that a program with trash in fd_array can't be loaded: 350 * only map and BTF file descriptors should be accepted. 351 */ 352 static void check_fd_array_cnt__fd_array_with_trash(void) 353 { 354 int extra_fds[3] = { -1, -1, -1 }; 355 int prog_fd = -1; 356 357 extra_fds[0] = new_map(); 358 if (!ASSERT_GE(extra_fds[0], 0, "new_map")) 359 goto cleanup; 360 extra_fds[1] = new_btf(); 361 if (!ASSERT_GE(extra_fds[1], 0, "new_btf")) 362 goto cleanup; 363 364 /* trash 1: not a file descriptor */ 365 extra_fds[2] = 0xbeef; 366 prog_fd = load_test_prog(extra_fds, 3); 367 if (!ASSERT_EQ(prog_fd, -EBADF, "prog should have been rejected with -EBADF")) 368 goto cleanup; 369 370 /* trash 2: not a map or btf */ 371 extra_fds[2] = socket(AF_INET, SOCK_STREAM, 0); 372 if (!ASSERT_GE(extra_fds[2], 0, "socket")) 373 goto cleanup; 374 375 prog_fd = load_test_prog(extra_fds, 3); 376 if (!ASSERT_EQ(prog_fd, -EINVAL, "prog should have been rejected with -EINVAL")) 377 goto cleanup; 378 379 /* Validate that the prog is ok if trash is removed */ 380 Close(extra_fds[2]); 381 extra_fds[2] = new_btf(); 382 if (!ASSERT_GE(extra_fds[2], 0, "new_btf")) 383 goto cleanup; 384 385 prog_fd = load_test_prog(extra_fds, 3); 386 if (!ASSERT_GE(prog_fd, 0, "prog should have been loaded")) 387 goto cleanup; 388 389 /* some fds might be invalid, so ignore return codes */ 390 cleanup: 391 Close(extra_fds[2]); 392 Close(extra_fds[1]); 393 Close(extra_fds[0]); 394 } 395 396 /* 397 * Test that a program with too big fd_array can't be loaded. 398 */ 399 static void check_fd_array_cnt__fd_array_too_big(void) 400 { 401 int extra_fds[65]; 402 int prog_fd = -1; 403 int i; 404 405 for (i = 0; i < 65; i++) { 406 extra_fds[i] = new_map(); 407 if (!ASSERT_GE(extra_fds[i], 0, "new_map")) 408 goto cleanup_fds; 409 } 410 411 prog_fd = load_test_prog(extra_fds, 65); 412 ASSERT_EQ(prog_fd, -E2BIG, "prog should have been rejected with -E2BIG"); 413 414 cleanup_fds: 415 while (i > 0) 416 Close(extra_fds[--i]); 417 } 418 419 void test_fd_array_cnt(void) 420 { 421 if (test__start_subtest("no-fd-array")) 422 check_fd_array_cnt__no_fd_array(); 423 424 if (test__start_subtest("fd-array-ok")) 425 check_fd_array_cnt__fd_array_ok(); 426 427 if (test__start_subtest("fd-array-dup-input")) 428 check_fd_array_cnt__duplicated_maps(); 429 430 if (test__start_subtest("fd-array-ref-maps-in-array")) 431 check_fd_array_cnt__referenced_maps_in_fd_array(); 432 433 if (test__start_subtest("fd-array-ref-btfs")) 434 check_fd_array_cnt__referenced_btfs(); 435 436 if (test__start_subtest("fd-array-trash-input")) 437 check_fd_array_cnt__fd_array_with_trash(); 438 439 if (test__start_subtest("fd-array-2big")) 440 check_fd_array_cnt__fd_array_too_big(); 441 } 442