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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 | // SPDX-License-Identifier: GPL-2.0-only /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com * Copyright (c) 2016 Facebook * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io */ #include <uapi/linux/btf.h> #include <linux/kernel.h> #include <linux/types.h> #include <linux/bpf.h> #include <linux/bpf_verifier.h> #include <linux/math64.h> #include <linux/string.h> #define verbose(env, fmt, args...) bpf_verifier_log_write(env, fmt, ##args) static bool bpf_verifier_log_attr_valid(const struct bpf_verifier_log *log) { /* ubuf and len_total should both be specified (or not) together */ if (!!log->ubuf != !!log->len_total) return false; /* log buf without log_level is meaningless */ if (log->ubuf && log->level == 0) return false; if (log->level & ~BPF_LOG_MASK) return false; if (log->len_total > UINT_MAX >> 2) return false; return true; } int bpf_vlog_init(struct bpf_verifier_log *log, u32 log_level, char __user *log_buf, u32 log_size) { log->level = log_level; log->ubuf = log_buf; log->len_total = log_size; /* log attributes have to be sane */ if (!bpf_verifier_log_attr_valid(log)) return -EINVAL; return 0; } static void bpf_vlog_update_len_max(struct bpf_verifier_log *log, u32 add_len) { /* add_len includes terminal \0, so no need for +1. */ u64 len = log->end_pos + add_len; /* log->len_max could be larger than our current len due to * bpf_vlog_reset() calls, so we maintain the max of any length at any * previous point */ if (len > UINT_MAX) log->len_max = UINT_MAX; else if (len > log->len_max) log->len_max = len; } void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt, va_list args) { u64 cur_pos; u32 new_n, n; n = vscnprintf(log->kbuf, BPF_VERIFIER_TMP_LOG_SIZE, fmt, args); if (log->level == BPF_LOG_KERNEL) { bool newline = n > 0 && log->kbuf[n - 1] == '\n'; pr_err("BPF: %s%s", log->kbuf, newline ? "" : "\n"); return; } n += 1; /* include terminating zero */ bpf_vlog_update_len_max(log, n); if (log->level & BPF_LOG_FIXED) { /* check if we have at least something to put into user buf */ new_n = 0; if (log->end_pos < log->len_total) { new_n = min_t(u32, log->len_total - log->end_pos, n); log->kbuf[new_n - 1] = '\0'; } cur_pos = log->end_pos; log->end_pos += n - 1; /* don't count terminating '\0' */ if (log->ubuf && new_n && copy_to_user(log->ubuf + cur_pos, log->kbuf, new_n)) goto fail; } else { u64 new_end, new_start; u32 buf_start, buf_end, new_n; new_end = log->end_pos + n; if (new_end - log->start_pos >= log->len_total) new_start = new_end - log->len_total; else new_start = log->start_pos; log->start_pos = new_start; log->end_pos = new_end - 1; /* don't count terminating '\0' */ if (!log->ubuf) return; new_n = min(n, log->len_total); cur_pos = new_end - new_n; div_u64_rem(cur_pos, log->len_total, &buf_start); div_u64_rem(new_end, log->len_total, &buf_end); /* new_end and buf_end are exclusive indices, so if buf_end is * exactly zero, then it actually points right to the end of * ubuf and there is no wrap around */ if (buf_end == 0) buf_end = log->len_total; /* if buf_start > buf_end, we wrapped around; * if buf_start == buf_end, then we fill ubuf completely; we * can't have buf_start == buf_end to mean that there is * nothing to write, because we always write at least * something, even if terminal '\0' */ if (buf_start < buf_end) { /* message fits within contiguous chunk of ubuf */ if (copy_to_user(log->ubuf + buf_start, log->kbuf + n - new_n, buf_end - buf_start)) goto fail; } else { /* message wraps around the end of ubuf, copy in two chunks */ if (copy_to_user(log->ubuf + buf_start, log->kbuf + n - new_n, log->len_total - buf_start)) goto fail; if (copy_to_user(log->ubuf, log->kbuf + n - buf_end, buf_end)) goto fail; } } return; fail: log->ubuf = NULL; } void bpf_vlog_reset(struct bpf_verifier_log *log, u64 new_pos) { char zero = 0; u32 pos; if (WARN_ON_ONCE(new_pos > log->end_pos)) return; if (!bpf_verifier_log_needed(log) || log->level == BPF_LOG_KERNEL) return; /* if position to which we reset is beyond current log window, * then we didn't preserve any useful content and should adjust * start_pos to end up with an empty log (start_pos == end_pos) */ log->end_pos = new_pos; if (log->end_pos < log->start_pos) log->start_pos = log->end_pos; if (!log->ubuf) return; if (log->level & BPF_LOG_FIXED) pos = log->end_pos + 1; else div_u64_rem(new_pos, log->len_total, &pos); if (pos < log->len_total && put_user(zero, log->ubuf + pos)) log->ubuf = NULL; } static void bpf_vlog_reverse_kbuf(char *buf, int len) { int i, j; for (i = 0, j = len - 1; i < j; i++, j--) swap(buf[i], buf[j]); } static int bpf_vlog_reverse_ubuf(struct bpf_verifier_log *log, int start, int end) { /* we split log->kbuf into two equal parts for both ends of array */ int n = sizeof(log->kbuf) / 2, nn; char *lbuf = log->kbuf, *rbuf = log->kbuf + n; /* Read ubuf's section [start, end) two chunks at a time, from left * and right side; within each chunk, swap all the bytes; after that * reverse the order of lbuf and rbuf and write result back to ubuf. * This way we'll end up with swapped contents of specified * [start, end) ubuf segment. */ while (end - start > 1) { nn = min(n, (end - start ) / 2); if (copy_from_user(lbuf, log->ubuf + start, nn)) return -EFAULT; if (copy_from_user(rbuf, log->ubuf + end - nn, nn)) return -EFAULT; bpf_vlog_reverse_kbuf(lbuf, nn); bpf_vlog_reverse_kbuf(rbuf, nn); /* we write lbuf to the right end of ubuf, while rbuf to the * left one to end up with properly reversed overall ubuf */ if (copy_to_user(log->ubuf + start, rbuf, nn)) return -EFAULT; if (copy_to_user(log->ubuf + end - nn, lbuf, nn)) return -EFAULT; start += nn; end -= nn; } return 0; } int bpf_vlog_finalize(struct bpf_verifier_log *log, u32 *log_size_actual) { u32 sublen; int err; *log_size_actual = 0; if (!log || log->level == 0 || log->level == BPF_LOG_KERNEL) return 0; if (!log->ubuf) goto skip_log_rotate; /* If we never truncated log, there is nothing to move around. */ if (log->start_pos == 0) goto skip_log_rotate; /* Otherwise we need to rotate log contents to make it start from the * buffer beginning and be a continuous zero-terminated string. Note * that if log->start_pos != 0 then we definitely filled up entire log * buffer with no gaps, and we just need to shift buffer contents to * the left by (log->start_pos % log->len_total) bytes. * * Unfortunately, user buffer could be huge and we don't want to * allocate temporary kernel memory of the same size just to shift * contents in a straightforward fashion. Instead, we'll be clever and * do in-place array rotation. This is a leetcode-style problem, which * could be solved by three rotations. * * Let's say we have log buffer that has to be shifted left by 7 bytes * (spaces and vertical bar is just for demonstrative purposes): * E F G H I J K | A B C D * * First, we reverse entire array: * D C B A | K J I H G F E * * Then we rotate first 4 bytes (DCBA) and separately last 7 bytes * (KJIHGFE), resulting in a properly rotated array: * A B C D | E F G H I J K * * We'll utilize log->kbuf to read user memory chunk by chunk, swap * bytes, and write them back. Doing it byte-by-byte would be * unnecessarily inefficient. Altogether we are going to read and * write each byte twice, for total 4 memory copies between kernel and * user space. */ /* length of the chopped off part that will be the beginning; * len(ABCD) in the example above */ div_u64_rem(log->start_pos, log->len_total, &sublen); sublen = log->len_total - sublen; err = bpf_vlog_reverse_ubuf(log, 0, log->len_total); err = err ?: bpf_vlog_reverse_ubuf(log, 0, sublen); err = err ?: bpf_vlog_reverse_ubuf(log, sublen, log->len_total); if (err) log->ubuf = NULL; skip_log_rotate: *log_size_actual = log->len_max; /* properly initialized log has either both ubuf!=NULL and len_total>0 * or ubuf==NULL and len_total==0, so if this condition doesn't hold, * we got a fault somewhere along the way, so report it back */ if (!!log->ubuf != !!log->len_total) return -EFAULT; /* did truncation actually happen? */ if (log->ubuf && log->len_max > log->len_total) return -ENOSPC; return 0; } /* log_level controls verbosity level of eBPF verifier. * bpf_verifier_log_write() is used to dump the verification trace to the log, * so the user can figure out what's wrong with the program */ __printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env, const char *fmt, ...) { va_list args; if (!bpf_verifier_log_needed(&env->log)) return; va_start(args, fmt); bpf_verifier_vlog(&env->log, fmt, args); va_end(args); } EXPORT_SYMBOL_GPL(bpf_verifier_log_write); __printf(2, 3) void bpf_log(struct bpf_verifier_log *log, const char *fmt, ...) { va_list args; if (!bpf_verifier_log_needed(log)) return; va_start(args, fmt); bpf_verifier_vlog(log, fmt, args); va_end(args); } EXPORT_SYMBOL_GPL(bpf_log); static const struct bpf_line_info * find_linfo(const struct bpf_verifier_env *env, u32 insn_off) { const struct bpf_line_info *linfo; const struct bpf_prog *prog; u32 nr_linfo; int l, r, m; prog = env->prog; nr_linfo = prog->aux->nr_linfo; if (!nr_linfo || insn_off >= prog->len) return NULL; linfo = prog->aux->linfo; /* Loop invariant: linfo[l].insn_off <= insns_off. * linfo[0].insn_off == 0 which always satisfies above condition. * Binary search is searching for rightmost linfo entry that satisfies * the above invariant, giving us the desired record that covers given * instruction offset. */ l = 0; r = nr_linfo - 1; while (l < r) { /* (r - l + 1) / 2 means we break a tie to the right, so if: * l=1, r=2, linfo[l].insn_off <= insn_off, linfo[r].insn_off > insn_off, * then m=2, we see that linfo[m].insn_off > insn_off, and so * r becomes 1 and we exit the loop with correct l==1. * If the tie was broken to the left, m=1 would end us up in * an endless loop where l and m stay at 1 and r stays at 2. */ m = l + (r - l + 1) / 2; if (linfo[m].insn_off <= insn_off) l = m; else r = m - 1; } return &linfo[l]; } static const char *ltrim(const char *s) { while (isspace(*s)) s++; return s; } __printf(3, 4) void verbose_linfo(struct bpf_verifier_env *env, u32 insn_off, const char *prefix_fmt, ...) { const struct bpf_line_info *linfo, *prev_linfo; const struct btf *btf; const char *s, *fname; if (!bpf_verifier_log_needed(&env->log)) return; prev_linfo = env->prev_linfo; linfo = find_linfo(env, insn_off); if (!linfo || linfo == prev_linfo) return; /* It often happens that two separate linfo records point to the same * source code line, but have differing column numbers. Given verifier * log doesn't emit column information, from user perspective we just * end up emitting the same source code line twice unnecessarily. * So instead check that previous and current linfo record point to * the same file (file_name_offs match) and the same line number, and * avoid emitting duplicated source code line in such case. */ if (prev_linfo && linfo->file_name_off == prev_linfo->file_name_off && BPF_LINE_INFO_LINE_NUM(linfo->line_col) == BPF_LINE_INFO_LINE_NUM(prev_linfo->line_col)) return; if (prefix_fmt) { va_list args; va_start(args, prefix_fmt); bpf_verifier_vlog(&env->log, prefix_fmt, args); va_end(args); } btf = env->prog->aux->btf; s = ltrim(btf_name_by_offset(btf, linfo->line_off)); verbose(env, "%s", s); /* source code line */ s = btf_name_by_offset(btf, linfo->file_name_off); /* leave only file name */ fname = strrchr(s, '/'); fname = fname ? fname + 1 : s; verbose(env, " @ %s:%u\n", fname, BPF_LINE_INFO_LINE_NUM(linfo->line_col)); env->prev_linfo = linfo; } static const char *btf_type_name(const struct btf *btf, u32 id) { return btf_name_by_offset(btf, btf_type_by_id(btf, id)->name_off); } /* string representation of 'enum bpf_reg_type' * * Note that reg_type_str() can not appear more than once in a single verbose() * statement. */ const char *reg_type_str(struct bpf_verifier_env *env, enum bpf_reg_type type) { char postfix[16] = {0}, prefix[64] = {0}; static const char * const str[] = { [NOT_INIT] = "?", [SCALAR_VALUE] = "scalar", [PTR_TO_CTX] = "ctx", [CONST_PTR_TO_MAP] = "map_ptr", [PTR_TO_MAP_VALUE] = "map_value", [PTR_TO_STACK] = "fp", [PTR_TO_PACKET] = "pkt", [PTR_TO_PACKET_META] = "pkt_meta", [PTR_TO_PACKET_END] = "pkt_end", [PTR_TO_FLOW_KEYS] = "flow_keys", [PTR_TO_SOCKET] = "sock", [PTR_TO_SOCK_COMMON] = "sock_common", [PTR_TO_TCP_SOCK] = "tcp_sock", [PTR_TO_TP_BUFFER] = "tp_buffer", [PTR_TO_XDP_SOCK] = "xdp_sock", [PTR_TO_BTF_ID] = "ptr_", [PTR_TO_MEM] = "mem", [PTR_TO_ARENA] = "arena", [PTR_TO_BUF] = "buf", [PTR_TO_FUNC] = "func", [PTR_TO_MAP_KEY] = "map_key", [CONST_PTR_TO_DYNPTR] = "dynptr_ptr", }; if (type & PTR_MAYBE_NULL) { if (base_type(type) == PTR_TO_BTF_ID) strncpy(postfix, "or_null_", 16); else strncpy(postfix, "_or_null", 16); } snprintf(prefix, sizeof(prefix), "%s%s%s%s%s%s%s", type & MEM_RDONLY ? "rdonly_" : "", type & MEM_RINGBUF ? "ringbuf_" : "", type & MEM_USER ? "user_" : "", type & MEM_PERCPU ? "percpu_" : "", type & MEM_RCU ? "rcu_" : "", type & PTR_UNTRUSTED ? "untrusted_" : "", type & PTR_TRUSTED ? "trusted_" : "" ); snprintf(env->tmp_str_buf, TMP_STR_BUF_LEN, "%s%s%s", prefix, str[base_type(type)], postfix); return env->tmp_str_buf; } const char *dynptr_type_str(enum bpf_dynptr_type type) { switch (type) { case BPF_DYNPTR_TYPE_LOCAL: return "local"; case BPF_DYNPTR_TYPE_RINGBUF: return "ringbuf"; case BPF_DYNPTR_TYPE_SKB: return "skb"; case BPF_DYNPTR_TYPE_XDP: return "xdp"; case BPF_DYNPTR_TYPE_INVALID: return "<invalid>"; default: WARN_ONCE(1, "unknown dynptr type %d\n", type); return "<unknown>"; } } const char *iter_type_str(const struct btf *btf, u32 btf_id) { if (!btf || btf_id == 0) return "<invalid>"; /* we already validated that type is valid and has conforming name */ return btf_type_name(btf, btf_id) + sizeof(ITER_PREFIX) - 1; } const char *iter_state_str(enum bpf_iter_state state) { switch (state) { case BPF_ITER_STATE_ACTIVE: return "active"; case BPF_ITER_STATE_DRAINED: return "drained"; case BPF_ITER_STATE_INVALID: return "<invalid>"; default: WARN_ONCE(1, "unknown iter state %d\n", state); return "<unknown>"; } } static char slot_type_char[] = { [STACK_INVALID] = '?', [STACK_SPILL] = 'r', [STACK_MISC] = 'm', [STACK_ZERO] = '0', [STACK_DYNPTR] = 'd', [STACK_ITER] = 'i', }; static void print_liveness(struct bpf_verifier_env *env, enum bpf_reg_liveness live) { if (live & (REG_LIVE_READ | REG_LIVE_WRITTEN | REG_LIVE_DONE)) verbose(env, "_"); if (live & REG_LIVE_READ) verbose(env, "r"); if (live & REG_LIVE_WRITTEN) verbose(env, "w"); if (live & REG_LIVE_DONE) verbose(env, "D"); } #define UNUM_MAX_DECIMAL U16_MAX #define SNUM_MAX_DECIMAL S16_MAX #define SNUM_MIN_DECIMAL S16_MIN static bool is_unum_decimal(u64 num) { return num <= UNUM_MAX_DECIMAL; } static bool is_snum_decimal(s64 num) { return num >= SNUM_MIN_DECIMAL && num <= SNUM_MAX_DECIMAL; } static void verbose_unum(struct bpf_verifier_env *env, u64 num) { if (is_unum_decimal(num)) verbose(env, "%llu", num); else verbose(env, "%#llx", num); } static void verbose_snum(struct bpf_verifier_env *env, s64 num) { if (is_snum_decimal(num)) verbose(env, "%lld", num); else verbose(env, "%#llx", num); } int tnum_strn(char *str, size_t size, struct tnum a) { /* print as a constant, if tnum is fully known */ if (a.mask == 0) { if (is_unum_decimal(a.value)) return snprintf(str, size, "%llu", a.value); else return snprintf(str, size, "%#llx", a.value); } return snprintf(str, size, "(%#llx; %#llx)", a.value, a.mask); } EXPORT_SYMBOL_GPL(tnum_strn); static void print_scalar_ranges(struct bpf_verifier_env *env, const struct bpf_reg_state *reg, const char **sep) { /* For signed ranges, we want to unify 64-bit and 32-bit values in the * output as much as possible, but there is a bit of a complication. * If we choose to print values as decimals, this is natural to do, * because negative 64-bit and 32-bit values >= -S32_MIN have the same * representation due to sign extension. But if we choose to print * them in hex format (see is_snum_decimal()), then sign extension is * misleading. * E.g., smin=-2 and smin32=-2 are exactly the same in decimal, but in * hex they will be smin=0xfffffffffffffffe and smin32=0xfffffffe, two * very different numbers. * So we avoid sign extension if we choose to print values in hex. */ struct { const char *name; u64 val; bool omit; } minmaxs[] = { {"smin", reg->smin_value, reg->smin_value == S64_MIN}, {"smax", reg->smax_value, reg->smax_value == S64_MAX}, {"umin", reg->umin_value, reg->umin_value == 0}, {"umax", reg->umax_value, reg->umax_value == U64_MAX}, {"smin32", is_snum_decimal((s64)reg->s32_min_value) ? (s64)reg->s32_min_value : (u32)reg->s32_min_value, reg->s32_min_value == S32_MIN}, {"smax32", is_snum_decimal((s64)reg->s32_max_value) ? (s64)reg->s32_max_value : (u32)reg->s32_max_value, reg->s32_max_value == S32_MAX}, {"umin32", reg->u32_min_value, reg->u32_min_value == 0}, {"umax32", reg->u32_max_value, reg->u32_max_value == U32_MAX}, }, *m1, *m2, *mend = &minmaxs[ARRAY_SIZE(minmaxs)]; bool neg1, neg2; for (m1 = &minmaxs[0]; m1 < mend; m1++) { if (m1->omit) continue; neg1 = m1->name[0] == 's' && (s64)m1->val < 0; verbose(env, "%s%s=", *sep, m1->name); *sep = ","; for (m2 = m1 + 2; m2 < mend; m2 += 2) { if (m2->omit || m2->val != m1->val) continue; /* don't mix negatives with positives */ neg2 = m2->name[0] == 's' && (s64)m2->val < 0; if (neg2 != neg1) continue; m2->omit = true; verbose(env, "%s=", m2->name); } if (m1->name[0] == 's') verbose_snum(env, m1->val); else verbose_unum(env, m1->val); } } static bool type_is_map_ptr(enum bpf_reg_type t) { switch (base_type(t)) { case CONST_PTR_TO_MAP: case PTR_TO_MAP_KEY: case PTR_TO_MAP_VALUE: return true; default: return false; } } /* * _a stands for append, was shortened to avoid multiline statements below. * This macro is used to output a comma separated list of attributes. */ #define verbose_a(fmt, ...) ({ verbose(env, "%s" fmt, sep, ##__VA_ARGS__); sep = ","; }) static void print_reg_state(struct bpf_verifier_env *env, const struct bpf_func_state *state, const struct bpf_reg_state *reg) { enum bpf_reg_type t; const char *sep = ""; t = reg->type; if (t == SCALAR_VALUE && reg->precise) verbose(env, "P"); if (t == SCALAR_VALUE && tnum_is_const(reg->var_off)) { /* reg->off should be 0 for SCALAR_VALUE */ verbose_snum(env, reg->var_off.value + reg->off); return; } verbose(env, "%s", reg_type_str(env, t)); if (t == PTR_TO_ARENA) return; if (t == PTR_TO_STACK) { if (state->frameno != reg->frameno) verbose(env, "[%d]", reg->frameno); if (tnum_is_const(reg->var_off)) { verbose_snum(env, reg->var_off.value + reg->off); return; } } if (base_type(t) == PTR_TO_BTF_ID) verbose(env, "%s", btf_type_name(reg->btf, reg->btf_id)); verbose(env, "("); if (reg->id) verbose_a("id=%d", reg->id); if (reg->ref_obj_id) verbose_a("ref_obj_id=%d", reg->ref_obj_id); if (type_is_non_owning_ref(reg->type)) verbose_a("%s", "non_own_ref"); if (type_is_map_ptr(t)) { if (reg->map_ptr->name[0]) verbose_a("map=%s", reg->map_ptr->name); verbose_a("ks=%d,vs=%d", reg->map_ptr->key_size, reg->map_ptr->value_size); } if (t != SCALAR_VALUE && reg->off) { verbose_a("off="); verbose_snum(env, reg->off); } if (type_is_pkt_pointer(t)) { verbose_a("r="); verbose_unum(env, reg->range); } if (base_type(t) == PTR_TO_MEM) { verbose_a("sz="); verbose_unum(env, reg->mem_size); } if (t == CONST_PTR_TO_DYNPTR) verbose_a("type=%s", dynptr_type_str(reg->dynptr.type)); if (tnum_is_const(reg->var_off)) { /* a pointer register with fixed offset */ if (reg->var_off.value) { verbose_a("imm="); verbose_snum(env, reg->var_off.value); } } else { print_scalar_ranges(env, reg, &sep); if (!tnum_is_unknown(reg->var_off)) { char tn_buf[48]; tnum_strn(tn_buf, sizeof(tn_buf), reg->var_off); verbose_a("var_off=%s", tn_buf); } } verbose(env, ")"); } void print_verifier_state(struct bpf_verifier_env *env, const struct bpf_func_state *state, bool print_all) { const struct bpf_reg_state *reg; int i; if (state->frameno) verbose(env, " frame%d:", state->frameno); for (i = 0; i < MAX_BPF_REG; i++) { reg = &state->regs[i]; if (reg->type == NOT_INIT) continue; if (!print_all && !reg_scratched(env, i)) continue; verbose(env, " R%d", i); print_liveness(env, reg->live); verbose(env, "="); print_reg_state(env, state, reg); } for (i = 0; i < state->allocated_stack / BPF_REG_SIZE; i++) { char types_buf[BPF_REG_SIZE + 1]; const char *sep = ""; bool valid = false; u8 slot_type; int j; if (!print_all && !stack_slot_scratched(env, i)) continue; for (j = 0; j < BPF_REG_SIZE; j++) { slot_type = state->stack[i].slot_type[j]; if (slot_type != STACK_INVALID) valid = true; types_buf[j] = slot_type_char[slot_type]; } types_buf[BPF_REG_SIZE] = 0; if (!valid) continue; reg = &state->stack[i].spilled_ptr; switch (state->stack[i].slot_type[BPF_REG_SIZE - 1]) { case STACK_SPILL: /* print MISC/ZERO/INVALID slots above subreg spill */ for (j = 0; j < BPF_REG_SIZE; j++) if (state->stack[i].slot_type[j] == STACK_SPILL) break; types_buf[j] = '\0'; verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE); print_liveness(env, reg->live); verbose(env, "=%s", types_buf); print_reg_state(env, state, reg); break; case STACK_DYNPTR: /* skip to main dynptr slot */ i += BPF_DYNPTR_NR_SLOTS - 1; reg = &state->stack[i].spilled_ptr; verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE); print_liveness(env, reg->live); verbose(env, "=dynptr_%s(", dynptr_type_str(reg->dynptr.type)); if (reg->id) verbose_a("id=%d", reg->id); if (reg->ref_obj_id) verbose_a("ref_id=%d", reg->ref_obj_id); if (reg->dynptr_id) verbose_a("dynptr_id=%d", reg->dynptr_id); verbose(env, ")"); break; case STACK_ITER: /* only main slot has ref_obj_id set; skip others */ if (!reg->ref_obj_id) continue; verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE); print_liveness(env, reg->live); verbose(env, "=iter_%s(ref_id=%d,state=%s,depth=%u)", iter_type_str(reg->iter.btf, reg->iter.btf_id), reg->ref_obj_id, iter_state_str(reg->iter.state), reg->iter.depth); break; case STACK_MISC: case STACK_ZERO: default: verbose(env, " fp%d", (-i - 1) * BPF_REG_SIZE); print_liveness(env, reg->live); verbose(env, "=%s", types_buf); break; } } if (state->acquired_refs && state->refs[0].id) { verbose(env, " refs=%d", state->refs[0].id); for (i = 1; i < state->acquired_refs; i++) if (state->refs[i].id) verbose(env, ",%d", state->refs[i].id); } if (state->in_callback_fn) verbose(env, " cb"); if (state->in_async_callback_fn) verbose(env, " async_cb"); verbose(env, "\n"); if (!print_all) mark_verifier_state_clean(env); } static inline u32 vlog_alignment(u32 pos) { return round_up(max(pos + BPF_LOG_MIN_ALIGNMENT / 2, BPF_LOG_ALIGNMENT), BPF_LOG_MIN_ALIGNMENT) - pos - 1; } void print_insn_state(struct bpf_verifier_env *env, const struct bpf_func_state *state) { if (env->prev_log_pos && env->prev_log_pos == env->log.end_pos) { /* remove new line character */ bpf_vlog_reset(&env->log, env->prev_log_pos - 1); verbose(env, "%*c;", vlog_alignment(env->prev_insn_print_pos), ' '); } else { verbose(env, "%d:", env->insn_idx); } print_verifier_state(env, state, false); } |