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