1 // SPDX-License-Identifier: GPL-2.0 2 #include <errno.h> 3 #include <stdlib.h> 4 #include <bpf/bpf.h> 5 #include <bpf/btf.h> 6 #include <bpf/libbpf.h> 7 #include <linux/btf.h> 8 #include <linux/err.h> 9 #include <linux/string.h> 10 #include <internal/lib.h> 11 #include <symbol/kallsyms.h> 12 #include "bpf-event.h" 13 #include "bpf-utils.h" 14 #include "debug.h" 15 #include "dso.h" 16 #include "symbol.h" 17 #include "machine.h" 18 #include "env.h" 19 #include "session.h" 20 #include "map.h" 21 #include "evlist.h" 22 #include "record.h" 23 #include "util/synthetic-events.h" 24 25 #ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID 26 struct btf *btf__load_from_kernel_by_id(__u32 id) 27 { 28 struct btf *btf; 29 #pragma GCC diagnostic push 30 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 31 int err = btf__get_from_id(id, &btf); 32 #pragma GCC diagnostic pop 33 34 return err ? ERR_PTR(err) : btf; 35 } 36 #endif 37 38 #ifndef HAVE_LIBBPF_BPF_PROG_LOAD 39 int bpf_prog_load(enum bpf_prog_type prog_type, 40 const char *prog_name __maybe_unused, 41 const char *license, 42 const struct bpf_insn *insns, size_t insn_cnt, 43 const struct bpf_prog_load_opts *opts) 44 { 45 #pragma GCC diagnostic push 46 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 47 return bpf_load_program(prog_type, insns, insn_cnt, license, 48 opts->kern_version, opts->log_buf, opts->log_size); 49 #pragma GCC diagnostic pop 50 } 51 #endif 52 53 #ifndef HAVE_LIBBPF_BPF_OBJECT__NEXT_PROGRAM 54 struct bpf_program * 55 bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev) 56 { 57 #pragma GCC diagnostic push 58 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 59 return bpf_program__next(prev, obj); 60 #pragma GCC diagnostic pop 61 } 62 #endif 63 64 #ifndef HAVE_LIBBPF_BPF_OBJECT__NEXT_MAP 65 struct bpf_map * 66 bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev) 67 { 68 #pragma GCC diagnostic push 69 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 70 return bpf_map__next(prev, obj); 71 #pragma GCC diagnostic pop 72 } 73 #endif 74 75 #ifndef HAVE_LIBBPF_BTF__RAW_DATA 76 const void * 77 btf__raw_data(const struct btf *btf_ro, __u32 *size) 78 { 79 #pragma GCC diagnostic push 80 #pragma GCC diagnostic ignored "-Wdeprecated-declarations" 81 return btf__get_raw_data(btf_ro, size); 82 #pragma GCC diagnostic pop 83 } 84 #endif 85 86 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len) 87 { 88 int ret = 0; 89 size_t i; 90 91 for (i = 0; i < len; i++) 92 ret += snprintf(buf + ret, size - ret, "%02x", data[i]); 93 return ret; 94 } 95 96 static int machine__process_bpf_event_load(struct machine *machine, 97 union perf_event *event, 98 struct perf_sample *sample __maybe_unused) 99 { 100 struct bpf_prog_info_node *info_node; 101 struct perf_env *env = machine->env; 102 struct perf_bpil *info_linear; 103 int id = event->bpf.id; 104 unsigned int i; 105 106 /* perf-record, no need to handle bpf-event */ 107 if (env == NULL) 108 return 0; 109 110 info_node = perf_env__find_bpf_prog_info(env, id); 111 if (!info_node) 112 return 0; 113 info_linear = info_node->info_linear; 114 115 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) { 116 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms); 117 u64 addr = addrs[i]; 118 struct map *map = maps__find(machine__kernel_maps(machine), addr); 119 120 if (map) { 121 map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO; 122 map->dso->bpf_prog.id = id; 123 map->dso->bpf_prog.sub_id = i; 124 map->dso->bpf_prog.env = env; 125 } 126 } 127 return 0; 128 } 129 130 int machine__process_bpf(struct machine *machine, union perf_event *event, 131 struct perf_sample *sample) 132 { 133 if (dump_trace) 134 perf_event__fprintf_bpf(event, stdout); 135 136 switch (event->bpf.type) { 137 case PERF_BPF_EVENT_PROG_LOAD: 138 return machine__process_bpf_event_load(machine, event, sample); 139 140 case PERF_BPF_EVENT_PROG_UNLOAD: 141 /* 142 * Do not free bpf_prog_info and btf of the program here, 143 * as annotation still need them. They will be freed at 144 * the end of the session. 145 */ 146 break; 147 default: 148 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 149 break; 150 } 151 return 0; 152 } 153 154 static int perf_env__fetch_btf(struct perf_env *env, 155 u32 btf_id, 156 struct btf *btf) 157 { 158 struct btf_node *node; 159 u32 data_size; 160 const void *data; 161 162 data = btf__raw_data(btf, &data_size); 163 164 node = malloc(data_size + sizeof(struct btf_node)); 165 if (!node) 166 return -1; 167 168 node->id = btf_id; 169 node->data_size = data_size; 170 memcpy(node->data, data, data_size); 171 172 if (!perf_env__insert_btf(env, node)) { 173 /* Insertion failed because of a duplicate. */ 174 free(node); 175 return -1; 176 } 177 return 0; 178 } 179 180 static int synthesize_bpf_prog_name(char *buf, int size, 181 struct bpf_prog_info *info, 182 struct btf *btf, 183 u32 sub_id) 184 { 185 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags); 186 void *func_infos = (void *)(uintptr_t)(info->func_info); 187 u32 sub_prog_cnt = info->nr_jited_ksyms; 188 const struct bpf_func_info *finfo; 189 const char *short_name = NULL; 190 const struct btf_type *t; 191 int name_len; 192 193 name_len = snprintf(buf, size, "bpf_prog_"); 194 name_len += snprintf_hex(buf + name_len, size - name_len, 195 prog_tags[sub_id], BPF_TAG_SIZE); 196 if (btf) { 197 finfo = func_infos + sub_id * info->func_info_rec_size; 198 t = btf__type_by_id(btf, finfo->type_id); 199 short_name = btf__name_by_offset(btf, t->name_off); 200 } else if (sub_id == 0 && sub_prog_cnt == 1) { 201 /* no subprog */ 202 if (info->name[0]) 203 short_name = info->name; 204 } else 205 short_name = "F"; 206 if (short_name) 207 name_len += snprintf(buf + name_len, size - name_len, 208 "_%s", short_name); 209 return name_len; 210 } 211 212 /* 213 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf 214 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And 215 * one PERF_RECORD_KSYMBOL is generated for each sub program. 216 * 217 * Returns: 218 * 0 for success; 219 * -1 for failures; 220 * -2 for lack of kernel support. 221 */ 222 static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, 223 perf_event__handler_t process, 224 struct machine *machine, 225 int fd, 226 union perf_event *event, 227 struct record_opts *opts) 228 { 229 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol; 230 struct perf_record_bpf_event *bpf_event = &event->bpf; 231 struct perf_tool *tool = session->tool; 232 struct bpf_prog_info_node *info_node; 233 struct perf_bpil *info_linear; 234 struct bpf_prog_info *info; 235 struct btf *btf = NULL; 236 struct perf_env *env; 237 u32 sub_prog_cnt, i; 238 int err = 0; 239 u64 arrays; 240 241 /* 242 * for perf-record and perf-report use header.env; 243 * otherwise, use global perf_env. 244 */ 245 env = session->data ? &session->header.env : &perf_env; 246 247 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 248 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 249 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 250 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 251 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 252 arrays |= 1UL << PERF_BPIL_LINE_INFO; 253 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 254 255 info_linear = get_bpf_prog_info_linear(fd, arrays); 256 if (IS_ERR_OR_NULL(info_linear)) { 257 info_linear = NULL; 258 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 259 return -1; 260 } 261 262 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { 263 free(info_linear); 264 pr_debug("%s: the kernel is too old, aborting\n", __func__); 265 return -2; 266 } 267 268 info = &info_linear->info; 269 if (!info->jited_ksyms) { 270 free(info_linear); 271 return -1; 272 } 273 274 /* number of ksyms, func_lengths, and tags should match */ 275 sub_prog_cnt = info->nr_jited_ksyms; 276 if (sub_prog_cnt != info->nr_prog_tags || 277 sub_prog_cnt != info->nr_jited_func_lens) { 278 free(info_linear); 279 return -1; 280 } 281 282 /* check BTF func info support */ 283 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { 284 /* btf func info number should be same as sub_prog_cnt */ 285 if (sub_prog_cnt != info->nr_func_info) { 286 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); 287 free(info_linear); 288 return -1; 289 } 290 btf = btf__load_from_kernel_by_id(info->btf_id); 291 if (libbpf_get_error(btf)) { 292 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id); 293 err = -1; 294 goto out; 295 } 296 perf_env__fetch_btf(env, info->btf_id, btf); 297 } 298 299 /* Synthesize PERF_RECORD_KSYMBOL */ 300 for (i = 0; i < sub_prog_cnt; i++) { 301 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 302 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 303 int name_len; 304 305 *ksymbol_event = (struct perf_record_ksymbol) { 306 .header = { 307 .type = PERF_RECORD_KSYMBOL, 308 .size = offsetof(struct perf_record_ksymbol, name), 309 }, 310 .addr = prog_addrs[i], 311 .len = prog_lens[i], 312 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 313 .flags = 0, 314 }; 315 316 name_len = synthesize_bpf_prog_name(ksymbol_event->name, 317 KSYM_NAME_LEN, info, btf, i); 318 ksymbol_event->header.size += PERF_ALIGN(name_len + 1, 319 sizeof(u64)); 320 321 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 322 event->header.size += machine->id_hdr_size; 323 err = perf_tool__process_synth_event(tool, event, 324 machine, process); 325 } 326 327 if (!opts->no_bpf_event) { 328 /* Synthesize PERF_RECORD_BPF_EVENT */ 329 *bpf_event = (struct perf_record_bpf_event) { 330 .header = { 331 .type = PERF_RECORD_BPF_EVENT, 332 .size = sizeof(struct perf_record_bpf_event), 333 }, 334 .type = PERF_BPF_EVENT_PROG_LOAD, 335 .flags = 0, 336 .id = info->id, 337 }; 338 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE); 339 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 340 event->header.size += machine->id_hdr_size; 341 342 /* save bpf_prog_info to env */ 343 info_node = malloc(sizeof(struct bpf_prog_info_node)); 344 if (!info_node) { 345 err = -1; 346 goto out; 347 } 348 349 info_node->info_linear = info_linear; 350 perf_env__insert_bpf_prog_info(env, info_node); 351 info_linear = NULL; 352 353 /* 354 * process after saving bpf_prog_info to env, so that 355 * required information is ready for look up 356 */ 357 err = perf_tool__process_synth_event(tool, event, 358 machine, process); 359 } 360 361 out: 362 free(info_linear); 363 btf__free(btf); 364 return err ? -1 : 0; 365 } 366 367 struct kallsyms_parse { 368 union perf_event *event; 369 perf_event__handler_t process; 370 struct machine *machine; 371 struct perf_tool *tool; 372 }; 373 374 static int 375 process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data) 376 { 377 struct machine *machine = data->machine; 378 union perf_event *event = data->event; 379 struct perf_record_ksymbol *ksymbol; 380 int len; 381 382 ksymbol = &event->ksymbol; 383 384 *ksymbol = (struct perf_record_ksymbol) { 385 .header = { 386 .type = PERF_RECORD_KSYMBOL, 387 .size = offsetof(struct perf_record_ksymbol, name), 388 }, 389 .addr = addr, 390 .len = page_size, 391 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 392 .flags = 0, 393 }; 394 395 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name); 396 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64)); 397 memset((void *) event + event->header.size, 0, machine->id_hdr_size); 398 event->header.size += machine->id_hdr_size; 399 400 return perf_tool__process_synth_event(data->tool, event, machine, 401 data->process); 402 } 403 404 static int 405 kallsyms_process_symbol(void *data, const char *_name, 406 char type __maybe_unused, u64 start) 407 { 408 char disp[KSYM_NAME_LEN]; 409 char *module, *name; 410 unsigned long id; 411 int err = 0; 412 413 module = strchr(_name, '\t'); 414 if (!module) 415 return 0; 416 417 /* We are going after [bpf] module ... */ 418 if (strcmp(module + 1, "[bpf]")) 419 return 0; 420 421 name = memdup(_name, (module - _name) + 1); 422 if (!name) 423 return -ENOMEM; 424 425 name[module - _name] = 0; 426 427 /* .. and only for trampolines and dispatchers */ 428 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) || 429 (sscanf(name, "bpf_dispatcher_%s", disp) == 1)) 430 err = process_bpf_image(name, start, data); 431 432 free(name); 433 return err; 434 } 435 436 int perf_event__synthesize_bpf_events(struct perf_session *session, 437 perf_event__handler_t process, 438 struct machine *machine, 439 struct record_opts *opts) 440 { 441 const char *kallsyms_filename = "/proc/kallsyms"; 442 struct kallsyms_parse arg; 443 union perf_event *event; 444 __u32 id = 0; 445 int err; 446 int fd; 447 448 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); 449 if (!event) 450 return -1; 451 452 /* Synthesize all the bpf programs in system. */ 453 while (true) { 454 err = bpf_prog_get_next_id(id, &id); 455 if (err) { 456 if (errno == ENOENT) { 457 err = 0; 458 break; 459 } 460 pr_debug("%s: can't get next program: %s%s\n", 461 __func__, strerror(errno), 462 errno == EINVAL ? " -- kernel too old?" : ""); 463 /* don't report error on old kernel or EPERM */ 464 err = (errno == EINVAL || errno == EPERM) ? 0 : -1; 465 break; 466 } 467 fd = bpf_prog_get_fd_by_id(id); 468 if (fd < 0) { 469 pr_debug("%s: failed to get fd for prog_id %u\n", 470 __func__, id); 471 continue; 472 } 473 474 err = perf_event__synthesize_one_bpf_prog(session, process, 475 machine, fd, 476 event, opts); 477 close(fd); 478 if (err) { 479 /* do not return error for old kernel */ 480 if (err == -2) 481 err = 0; 482 break; 483 } 484 } 485 486 /* Synthesize all the bpf images - trampolines/dispatchers. */ 487 if (symbol_conf.kallsyms_name != NULL) 488 kallsyms_filename = symbol_conf.kallsyms_name; 489 490 arg = (struct kallsyms_parse) { 491 .event = event, 492 .process = process, 493 .machine = machine, 494 .tool = session->tool, 495 }; 496 497 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) { 498 pr_err("%s: failed to synthesize bpf images: %s\n", 499 __func__, strerror(errno)); 500 } 501 502 free(event); 503 return err; 504 } 505 506 static void perf_env__add_bpf_info(struct perf_env *env, u32 id) 507 { 508 struct bpf_prog_info_node *info_node; 509 struct perf_bpil *info_linear; 510 struct btf *btf = NULL; 511 u64 arrays; 512 u32 btf_id; 513 int fd; 514 515 fd = bpf_prog_get_fd_by_id(id); 516 if (fd < 0) 517 return; 518 519 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 520 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 521 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 522 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 523 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 524 arrays |= 1UL << PERF_BPIL_LINE_INFO; 525 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 526 527 info_linear = get_bpf_prog_info_linear(fd, arrays); 528 if (IS_ERR_OR_NULL(info_linear)) { 529 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 530 goto out; 531 } 532 533 btf_id = info_linear->info.btf_id; 534 535 info_node = malloc(sizeof(struct bpf_prog_info_node)); 536 if (info_node) { 537 info_node->info_linear = info_linear; 538 perf_env__insert_bpf_prog_info(env, info_node); 539 } else 540 free(info_linear); 541 542 if (btf_id == 0) 543 goto out; 544 545 btf = btf__load_from_kernel_by_id(btf_id); 546 if (libbpf_get_error(btf)) { 547 pr_debug("%s: failed to get BTF of id %u, aborting\n", 548 __func__, btf_id); 549 goto out; 550 } 551 perf_env__fetch_btf(env, btf_id, btf); 552 553 out: 554 btf__free(btf); 555 close(fd); 556 } 557 558 static int bpf_event__sb_cb(union perf_event *event, void *data) 559 { 560 struct perf_env *env = data; 561 562 if (event->header.type != PERF_RECORD_BPF_EVENT) 563 return -1; 564 565 switch (event->bpf.type) { 566 case PERF_BPF_EVENT_PROG_LOAD: 567 perf_env__add_bpf_info(env, event->bpf.id); 568 569 case PERF_BPF_EVENT_PROG_UNLOAD: 570 /* 571 * Do not free bpf_prog_info and btf of the program here, 572 * as annotation still need them. They will be freed at 573 * the end of the session. 574 */ 575 break; 576 default: 577 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 578 break; 579 } 580 581 return 0; 582 } 583 584 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) 585 { 586 struct perf_event_attr attr = { 587 .type = PERF_TYPE_SOFTWARE, 588 .config = PERF_COUNT_SW_DUMMY, 589 .sample_id_all = 1, 590 .watermark = 1, 591 .bpf_event = 1, 592 .size = sizeof(attr), /* to capture ABI version */ 593 }; 594 595 /* 596 * Older gcc versions don't support designated initializers, like above, 597 * for unnamed union members, such as the following: 598 */ 599 attr.wakeup_watermark = 1; 600 601 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); 602 } 603 604 void bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, 605 struct perf_env *env, 606 FILE *fp) 607 { 608 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 609 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 610 char name[KSYM_NAME_LEN]; 611 struct btf *btf = NULL; 612 u32 sub_prog_cnt, i; 613 614 sub_prog_cnt = info->nr_jited_ksyms; 615 if (sub_prog_cnt != info->nr_prog_tags || 616 sub_prog_cnt != info->nr_jited_func_lens) 617 return; 618 619 if (info->btf_id) { 620 struct btf_node *node; 621 622 node = perf_env__find_btf(env, info->btf_id); 623 if (node) 624 btf = btf__new((__u8 *)(node->data), 625 node->data_size); 626 } 627 628 if (sub_prog_cnt == 1) { 629 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0); 630 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n", 631 info->id, name, prog_addrs[0], prog_lens[0]); 632 goto out; 633 } 634 635 fprintf(fp, "# bpf_prog_info %u:\n", info->id); 636 for (i = 0; i < sub_prog_cnt; i++) { 637 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i); 638 639 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n", 640 i, name, prog_addrs[i], prog_lens[i]); 641 } 642 out: 643 btf__free(btf); 644 } 645