1 // SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) 2 3 /* 4 * common eBPF ELF operations. 5 * 6 * Copyright (C) 2013-2015 Alexei Starovoitov <ast@kernel.org> 7 * Copyright (C) 2015 Wang Nan <wangnan0@huawei.com> 8 * Copyright (C) 2015 Huawei Inc. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU Lesser General Public 12 * License as published by the Free Software Foundation; 13 * version 2.1 of the License (not later!) 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU Lesser General Public License for more details. 19 * 20 * You should have received a copy of the GNU Lesser General Public 21 * License along with this program; if not, see <http://www.gnu.org/licenses> 22 */ 23 24 #include <stdlib.h> 25 #include <string.h> 26 #include <memory.h> 27 #include <unistd.h> 28 #include <asm/unistd.h> 29 #include <errno.h> 30 #include <linux/bpf.h> 31 #include "bpf.h" 32 #include "libbpf.h" 33 #include "libbpf_internal.h" 34 35 /* 36 * When building perf, unistd.h is overridden. __NR_bpf is 37 * required to be defined explicitly. 38 */ 39 #ifndef __NR_bpf 40 # if defined(__i386__) 41 # define __NR_bpf 357 42 # elif defined(__x86_64__) 43 # define __NR_bpf 321 44 # elif defined(__aarch64__) 45 # define __NR_bpf 280 46 # elif defined(__sparc__) 47 # define __NR_bpf 349 48 # elif defined(__s390__) 49 # define __NR_bpf 351 50 # elif defined(__arc__) 51 # define __NR_bpf 280 52 # else 53 # error __NR_bpf not defined. libbpf does not support your arch. 54 # endif 55 #endif 56 57 static inline __u64 ptr_to_u64(const void *ptr) 58 { 59 return (__u64) (unsigned long) ptr; 60 } 61 62 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, 63 unsigned int size) 64 { 65 return syscall(__NR_bpf, cmd, attr, size); 66 } 67 68 static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size) 69 { 70 int fd; 71 72 do { 73 fd = sys_bpf(BPF_PROG_LOAD, attr, size); 74 } while (fd < 0 && errno == EAGAIN); 75 76 return fd; 77 } 78 79 int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) 80 { 81 union bpf_attr attr; 82 83 memset(&attr, '\0', sizeof(attr)); 84 85 attr.map_type = create_attr->map_type; 86 attr.key_size = create_attr->key_size; 87 attr.value_size = create_attr->value_size; 88 attr.max_entries = create_attr->max_entries; 89 attr.map_flags = create_attr->map_flags; 90 if (create_attr->name) 91 memcpy(attr.map_name, create_attr->name, 92 min(strlen(create_attr->name), BPF_OBJ_NAME_LEN - 1)); 93 attr.numa_node = create_attr->numa_node; 94 attr.btf_fd = create_attr->btf_fd; 95 attr.btf_key_type_id = create_attr->btf_key_type_id; 96 attr.btf_value_type_id = create_attr->btf_value_type_id; 97 attr.map_ifindex = create_attr->map_ifindex; 98 attr.inner_map_fd = create_attr->inner_map_fd; 99 100 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 101 } 102 103 int bpf_create_map_node(enum bpf_map_type map_type, const char *name, 104 int key_size, int value_size, int max_entries, 105 __u32 map_flags, int node) 106 { 107 struct bpf_create_map_attr map_attr = {}; 108 109 map_attr.name = name; 110 map_attr.map_type = map_type; 111 map_attr.map_flags = map_flags; 112 map_attr.key_size = key_size; 113 map_attr.value_size = value_size; 114 map_attr.max_entries = max_entries; 115 if (node >= 0) { 116 map_attr.numa_node = node; 117 map_attr.map_flags |= BPF_F_NUMA_NODE; 118 } 119 120 return bpf_create_map_xattr(&map_attr); 121 } 122 123 int bpf_create_map(enum bpf_map_type map_type, int key_size, 124 int value_size, int max_entries, __u32 map_flags) 125 { 126 struct bpf_create_map_attr map_attr = {}; 127 128 map_attr.map_type = map_type; 129 map_attr.map_flags = map_flags; 130 map_attr.key_size = key_size; 131 map_attr.value_size = value_size; 132 map_attr.max_entries = max_entries; 133 134 return bpf_create_map_xattr(&map_attr); 135 } 136 137 int bpf_create_map_name(enum bpf_map_type map_type, const char *name, 138 int key_size, int value_size, int max_entries, 139 __u32 map_flags) 140 { 141 struct bpf_create_map_attr map_attr = {}; 142 143 map_attr.name = name; 144 map_attr.map_type = map_type; 145 map_attr.map_flags = map_flags; 146 map_attr.key_size = key_size; 147 map_attr.value_size = value_size; 148 map_attr.max_entries = max_entries; 149 150 return bpf_create_map_xattr(&map_attr); 151 } 152 153 int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name, 154 int key_size, int inner_map_fd, int max_entries, 155 __u32 map_flags, int node) 156 { 157 union bpf_attr attr; 158 159 memset(&attr, '\0', sizeof(attr)); 160 161 attr.map_type = map_type; 162 attr.key_size = key_size; 163 attr.value_size = 4; 164 attr.inner_map_fd = inner_map_fd; 165 attr.max_entries = max_entries; 166 attr.map_flags = map_flags; 167 if (name) 168 memcpy(attr.map_name, name, 169 min(strlen(name), BPF_OBJ_NAME_LEN - 1)); 170 171 if (node >= 0) { 172 attr.map_flags |= BPF_F_NUMA_NODE; 173 attr.numa_node = node; 174 } 175 176 return sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr)); 177 } 178 179 int bpf_create_map_in_map(enum bpf_map_type map_type, const char *name, 180 int key_size, int inner_map_fd, int max_entries, 181 __u32 map_flags) 182 { 183 return bpf_create_map_in_map_node(map_type, name, key_size, 184 inner_map_fd, max_entries, map_flags, 185 -1); 186 } 187 188 static void * 189 alloc_zero_tailing_info(const void *orecord, __u32 cnt, 190 __u32 actual_rec_size, __u32 expected_rec_size) 191 { 192 __u64 info_len = (__u64)actual_rec_size * cnt; 193 void *info, *nrecord; 194 int i; 195 196 info = malloc(info_len); 197 if (!info) 198 return NULL; 199 200 /* zero out bytes kernel does not understand */ 201 nrecord = info; 202 for (i = 0; i < cnt; i++) { 203 memcpy(nrecord, orecord, expected_rec_size); 204 memset(nrecord + expected_rec_size, 0, 205 actual_rec_size - expected_rec_size); 206 orecord += actual_rec_size; 207 nrecord += actual_rec_size; 208 } 209 210 return info; 211 } 212 213 int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, 214 char *log_buf, size_t log_buf_sz) 215 { 216 void *finfo = NULL, *linfo = NULL; 217 union bpf_attr attr; 218 __u32 log_level; 219 int fd; 220 221 if (!load_attr || !log_buf != !log_buf_sz) 222 return -EINVAL; 223 224 log_level = load_attr->log_level; 225 if (log_level > (4 | 2 | 1) || (log_level && !log_buf)) 226 return -EINVAL; 227 228 memset(&attr, 0, sizeof(attr)); 229 attr.prog_type = load_attr->prog_type; 230 attr.expected_attach_type = load_attr->expected_attach_type; 231 if (attr.prog_type == BPF_PROG_TYPE_TRACING) { 232 attr.attach_btf_id = load_attr->attach_btf_id; 233 attr.attach_prog_fd = load_attr->attach_prog_fd; 234 } else { 235 attr.prog_ifindex = load_attr->prog_ifindex; 236 attr.kern_version = load_attr->kern_version; 237 } 238 attr.insn_cnt = (__u32)load_attr->insns_cnt; 239 attr.insns = ptr_to_u64(load_attr->insns); 240 attr.license = ptr_to_u64(load_attr->license); 241 242 attr.log_level = log_level; 243 if (log_level) { 244 attr.log_buf = ptr_to_u64(log_buf); 245 attr.log_size = log_buf_sz; 246 } else { 247 attr.log_buf = ptr_to_u64(NULL); 248 attr.log_size = 0; 249 } 250 251 attr.prog_btf_fd = load_attr->prog_btf_fd; 252 attr.func_info_rec_size = load_attr->func_info_rec_size; 253 attr.func_info_cnt = load_attr->func_info_cnt; 254 attr.func_info = ptr_to_u64(load_attr->func_info); 255 attr.line_info_rec_size = load_attr->line_info_rec_size; 256 attr.line_info_cnt = load_attr->line_info_cnt; 257 attr.line_info = ptr_to_u64(load_attr->line_info); 258 if (load_attr->name) 259 memcpy(attr.prog_name, load_attr->name, 260 min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1)); 261 attr.prog_flags = load_attr->prog_flags; 262 263 fd = sys_bpf_prog_load(&attr, sizeof(attr)); 264 if (fd >= 0) 265 return fd; 266 267 /* After bpf_prog_load, the kernel may modify certain attributes 268 * to give user space a hint how to deal with loading failure. 269 * Check to see whether we can make some changes and load again. 270 */ 271 while (errno == E2BIG && (!finfo || !linfo)) { 272 if (!finfo && attr.func_info_cnt && 273 attr.func_info_rec_size < load_attr->func_info_rec_size) { 274 /* try with corrected func info records */ 275 finfo = alloc_zero_tailing_info(load_attr->func_info, 276 load_attr->func_info_cnt, 277 load_attr->func_info_rec_size, 278 attr.func_info_rec_size); 279 if (!finfo) 280 goto done; 281 282 attr.func_info = ptr_to_u64(finfo); 283 attr.func_info_rec_size = load_attr->func_info_rec_size; 284 } else if (!linfo && attr.line_info_cnt && 285 attr.line_info_rec_size < 286 load_attr->line_info_rec_size) { 287 linfo = alloc_zero_tailing_info(load_attr->line_info, 288 load_attr->line_info_cnt, 289 load_attr->line_info_rec_size, 290 attr.line_info_rec_size); 291 if (!linfo) 292 goto done; 293 294 attr.line_info = ptr_to_u64(linfo); 295 attr.line_info_rec_size = load_attr->line_info_rec_size; 296 } else { 297 break; 298 } 299 300 fd = sys_bpf_prog_load(&attr, sizeof(attr)); 301 302 if (fd >= 0) 303 goto done; 304 } 305 306 if (log_level || !log_buf) 307 goto done; 308 309 /* Try again with log */ 310 attr.log_buf = ptr_to_u64(log_buf); 311 attr.log_size = log_buf_sz; 312 attr.log_level = 1; 313 log_buf[0] = 0; 314 fd = sys_bpf_prog_load(&attr, sizeof(attr)); 315 done: 316 free(finfo); 317 free(linfo); 318 return fd; 319 } 320 321 int bpf_load_program(enum bpf_prog_type type, const struct bpf_insn *insns, 322 size_t insns_cnt, const char *license, 323 __u32 kern_version, char *log_buf, 324 size_t log_buf_sz) 325 { 326 struct bpf_load_program_attr load_attr; 327 328 memset(&load_attr, 0, sizeof(struct bpf_load_program_attr)); 329 load_attr.prog_type = type; 330 load_attr.expected_attach_type = 0; 331 load_attr.name = NULL; 332 load_attr.insns = insns; 333 load_attr.insns_cnt = insns_cnt; 334 load_attr.license = license; 335 load_attr.kern_version = kern_version; 336 337 return bpf_load_program_xattr(&load_attr, log_buf, log_buf_sz); 338 } 339 340 int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, 341 size_t insns_cnt, __u32 prog_flags, const char *license, 342 __u32 kern_version, char *log_buf, size_t log_buf_sz, 343 int log_level) 344 { 345 union bpf_attr attr; 346 347 memset(&attr, 0, sizeof(attr)); 348 attr.prog_type = type; 349 attr.insn_cnt = (__u32)insns_cnt; 350 attr.insns = ptr_to_u64(insns); 351 attr.license = ptr_to_u64(license); 352 attr.log_buf = ptr_to_u64(log_buf); 353 attr.log_size = log_buf_sz; 354 attr.log_level = log_level; 355 log_buf[0] = 0; 356 attr.kern_version = kern_version; 357 attr.prog_flags = prog_flags; 358 359 return sys_bpf_prog_load(&attr, sizeof(attr)); 360 } 361 362 int bpf_map_update_elem(int fd, const void *key, const void *value, 363 __u64 flags) 364 { 365 union bpf_attr attr; 366 367 memset(&attr, 0, sizeof(attr)); 368 attr.map_fd = fd; 369 attr.key = ptr_to_u64(key); 370 attr.value = ptr_to_u64(value); 371 attr.flags = flags; 372 373 return sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr)); 374 } 375 376 int bpf_map_lookup_elem(int fd, const void *key, void *value) 377 { 378 union bpf_attr attr; 379 380 memset(&attr, 0, sizeof(attr)); 381 attr.map_fd = fd; 382 attr.key = ptr_to_u64(key); 383 attr.value = ptr_to_u64(value); 384 385 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 386 } 387 388 int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags) 389 { 390 union bpf_attr attr; 391 392 memset(&attr, 0, sizeof(attr)); 393 attr.map_fd = fd; 394 attr.key = ptr_to_u64(key); 395 attr.value = ptr_to_u64(value); 396 attr.flags = flags; 397 398 return sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr)); 399 } 400 401 int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value) 402 { 403 union bpf_attr attr; 404 405 memset(&attr, 0, sizeof(attr)); 406 attr.map_fd = fd; 407 attr.key = ptr_to_u64(key); 408 attr.value = ptr_to_u64(value); 409 410 return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr)); 411 } 412 413 int bpf_map_delete_elem(int fd, const void *key) 414 { 415 union bpf_attr attr; 416 417 memset(&attr, 0, sizeof(attr)); 418 attr.map_fd = fd; 419 attr.key = ptr_to_u64(key); 420 421 return sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr)); 422 } 423 424 int bpf_map_get_next_key(int fd, const void *key, void *next_key) 425 { 426 union bpf_attr attr; 427 428 memset(&attr, 0, sizeof(attr)); 429 attr.map_fd = fd; 430 attr.key = ptr_to_u64(key); 431 attr.next_key = ptr_to_u64(next_key); 432 433 return sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr)); 434 } 435 436 int bpf_map_freeze(int fd) 437 { 438 union bpf_attr attr; 439 440 memset(&attr, 0, sizeof(attr)); 441 attr.map_fd = fd; 442 443 return sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr)); 444 } 445 446 int bpf_obj_pin(int fd, const char *pathname) 447 { 448 union bpf_attr attr; 449 450 memset(&attr, 0, sizeof(attr)); 451 attr.pathname = ptr_to_u64((void *)pathname); 452 attr.bpf_fd = fd; 453 454 return sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr)); 455 } 456 457 int bpf_obj_get(const char *pathname) 458 { 459 union bpf_attr attr; 460 461 memset(&attr, 0, sizeof(attr)); 462 attr.pathname = ptr_to_u64((void *)pathname); 463 464 return sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr)); 465 } 466 467 int bpf_prog_attach(int prog_fd, int target_fd, enum bpf_attach_type type, 468 unsigned int flags) 469 { 470 union bpf_attr attr; 471 472 memset(&attr, 0, sizeof(attr)); 473 attr.target_fd = target_fd; 474 attr.attach_bpf_fd = prog_fd; 475 attr.attach_type = type; 476 attr.attach_flags = flags; 477 478 return sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr)); 479 } 480 481 int bpf_prog_detach(int target_fd, enum bpf_attach_type type) 482 { 483 union bpf_attr attr; 484 485 memset(&attr, 0, sizeof(attr)); 486 attr.target_fd = target_fd; 487 attr.attach_type = type; 488 489 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 490 } 491 492 int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type) 493 { 494 union bpf_attr attr; 495 496 memset(&attr, 0, sizeof(attr)); 497 attr.target_fd = target_fd; 498 attr.attach_bpf_fd = prog_fd; 499 attr.attach_type = type; 500 501 return sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr)); 502 } 503 504 int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags, 505 __u32 *attach_flags, __u32 *prog_ids, __u32 *prog_cnt) 506 { 507 union bpf_attr attr; 508 int ret; 509 510 memset(&attr, 0, sizeof(attr)); 511 attr.query.target_fd = target_fd; 512 attr.query.attach_type = type; 513 attr.query.query_flags = query_flags; 514 attr.query.prog_cnt = *prog_cnt; 515 attr.query.prog_ids = ptr_to_u64(prog_ids); 516 517 ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr)); 518 if (attach_flags) 519 *attach_flags = attr.query.attach_flags; 520 *prog_cnt = attr.query.prog_cnt; 521 return ret; 522 } 523 524 int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size, 525 void *data_out, __u32 *size_out, __u32 *retval, 526 __u32 *duration) 527 { 528 union bpf_attr attr; 529 int ret; 530 531 memset(&attr, 0, sizeof(attr)); 532 attr.test.prog_fd = prog_fd; 533 attr.test.data_in = ptr_to_u64(data); 534 attr.test.data_out = ptr_to_u64(data_out); 535 attr.test.data_size_in = size; 536 attr.test.repeat = repeat; 537 538 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 539 if (size_out) 540 *size_out = attr.test.data_size_out; 541 if (retval) 542 *retval = attr.test.retval; 543 if (duration) 544 *duration = attr.test.duration; 545 return ret; 546 } 547 548 int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr) 549 { 550 union bpf_attr attr; 551 int ret; 552 553 if (!test_attr->data_out && test_attr->data_size_out > 0) 554 return -EINVAL; 555 556 memset(&attr, 0, sizeof(attr)); 557 attr.test.prog_fd = test_attr->prog_fd; 558 attr.test.data_in = ptr_to_u64(test_attr->data_in); 559 attr.test.data_out = ptr_to_u64(test_attr->data_out); 560 attr.test.data_size_in = test_attr->data_size_in; 561 attr.test.data_size_out = test_attr->data_size_out; 562 attr.test.ctx_in = ptr_to_u64(test_attr->ctx_in); 563 attr.test.ctx_out = ptr_to_u64(test_attr->ctx_out); 564 attr.test.ctx_size_in = test_attr->ctx_size_in; 565 attr.test.ctx_size_out = test_attr->ctx_size_out; 566 attr.test.repeat = test_attr->repeat; 567 568 ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr)); 569 test_attr->data_size_out = attr.test.data_size_out; 570 test_attr->ctx_size_out = attr.test.ctx_size_out; 571 test_attr->retval = attr.test.retval; 572 test_attr->duration = attr.test.duration; 573 return ret; 574 } 575 576 static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd) 577 { 578 union bpf_attr attr; 579 int err; 580 581 memset(&attr, 0, sizeof(attr)); 582 attr.start_id = start_id; 583 584 err = sys_bpf(cmd, &attr, sizeof(attr)); 585 if (!err) 586 *next_id = attr.next_id; 587 588 return err; 589 } 590 591 int bpf_prog_get_next_id(__u32 start_id, __u32 *next_id) 592 { 593 return bpf_obj_get_next_id(start_id, next_id, BPF_PROG_GET_NEXT_ID); 594 } 595 596 int bpf_map_get_next_id(__u32 start_id, __u32 *next_id) 597 { 598 return bpf_obj_get_next_id(start_id, next_id, BPF_MAP_GET_NEXT_ID); 599 } 600 601 int bpf_btf_get_next_id(__u32 start_id, __u32 *next_id) 602 { 603 return bpf_obj_get_next_id(start_id, next_id, BPF_BTF_GET_NEXT_ID); 604 } 605 606 int bpf_prog_get_fd_by_id(__u32 id) 607 { 608 union bpf_attr attr; 609 610 memset(&attr, 0, sizeof(attr)); 611 attr.prog_id = id; 612 613 return sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr)); 614 } 615 616 int bpf_map_get_fd_by_id(__u32 id) 617 { 618 union bpf_attr attr; 619 620 memset(&attr, 0, sizeof(attr)); 621 attr.map_id = id; 622 623 return sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr)); 624 } 625 626 int bpf_btf_get_fd_by_id(__u32 id) 627 { 628 union bpf_attr attr; 629 630 memset(&attr, 0, sizeof(attr)); 631 attr.btf_id = id; 632 633 return sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr)); 634 } 635 636 int bpf_obj_get_info_by_fd(int prog_fd, void *info, __u32 *info_len) 637 { 638 union bpf_attr attr; 639 int err; 640 641 memset(&attr, 0, sizeof(attr)); 642 attr.info.bpf_fd = prog_fd; 643 attr.info.info_len = *info_len; 644 attr.info.info = ptr_to_u64(info); 645 646 err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr)); 647 if (!err) 648 *info_len = attr.info.info_len; 649 650 return err; 651 } 652 653 int bpf_raw_tracepoint_open(const char *name, int prog_fd) 654 { 655 union bpf_attr attr; 656 657 memset(&attr, 0, sizeof(attr)); 658 attr.raw_tracepoint.name = ptr_to_u64(name); 659 attr.raw_tracepoint.prog_fd = prog_fd; 660 661 return sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr)); 662 } 663 664 int bpf_load_btf(void *btf, __u32 btf_size, char *log_buf, __u32 log_buf_size, 665 bool do_log) 666 { 667 union bpf_attr attr = {}; 668 int fd; 669 670 attr.btf = ptr_to_u64(btf); 671 attr.btf_size = btf_size; 672 673 retry: 674 if (do_log && log_buf && log_buf_size) { 675 attr.btf_log_level = 1; 676 attr.btf_log_size = log_buf_size; 677 attr.btf_log_buf = ptr_to_u64(log_buf); 678 } 679 680 fd = sys_bpf(BPF_BTF_LOAD, &attr, sizeof(attr)); 681 if (fd == -1 && !do_log && log_buf && log_buf_size) { 682 do_log = true; 683 goto retry; 684 } 685 686 return fd; 687 } 688 689 int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len, 690 __u32 *prog_id, __u32 *fd_type, __u64 *probe_offset, 691 __u64 *probe_addr) 692 { 693 union bpf_attr attr = {}; 694 int err; 695 696 attr.task_fd_query.pid = pid; 697 attr.task_fd_query.fd = fd; 698 attr.task_fd_query.flags = flags; 699 attr.task_fd_query.buf = ptr_to_u64(buf); 700 attr.task_fd_query.buf_len = *buf_len; 701 702 err = sys_bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr)); 703 *buf_len = attr.task_fd_query.buf_len; 704 *prog_id = attr.task_fd_query.prog_id; 705 *fd_type = attr.task_fd_query.fd_type; 706 *probe_offset = attr.task_fd_query.probe_offset; 707 *probe_addr = attr.task_fd_query.probe_addr; 708 709 return err; 710 } 711