1 // SPDX-License-Identifier: GPL-2.0 2 #include <errno.h> 3 #include <stddef.h> 4 #include <stdint.h> 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <string.h> 8 #include <bpf/bpf.h> 9 #include <bpf/btf.h> 10 #include <bpf/libbpf.h> 11 #include <linux/bpf.h> 12 #include <linux/btf.h> 13 #include <linux/err.h> 14 #include <linux/perf_event.h> 15 #include <linux/string.h> 16 #include <linux/zalloc.h> 17 #include <internal/lib.h> 18 #include <perf/event.h> 19 #include <symbol/kallsyms.h> 20 #include "bpf-event.h" 21 #include "bpf-utils.h" 22 #include "debug.h" 23 #include "dso.h" 24 #include "symbol.h" 25 #include "machine.h" 26 #include "env.h" 27 #include "session.h" 28 #include "map.h" 29 #include "evlist.h" 30 #include "record.h" 31 #include "util/synthetic-events.h" 32 33 static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len) 34 { 35 int ret = 0; 36 size_t i; 37 38 for (i = 0; i < len; i++) 39 ret += snprintf(buf + ret, size - ret, "%02x", data[i]); 40 return ret; 41 } 42 43 static int machine__process_bpf_event_load(struct machine *machine, 44 union perf_event *event, 45 struct perf_sample *sample __maybe_unused) 46 { 47 struct bpf_prog_info_node *info_node; 48 struct perf_env *env = machine->env; 49 struct perf_bpil *info_linear; 50 int id = event->bpf.id; 51 unsigned int i; 52 53 /* perf-record, no need to handle bpf-event */ 54 if (env == NULL) 55 return 0; 56 57 info_node = perf_env__find_bpf_prog_info(env, id); 58 if (!info_node) 59 return 0; 60 info_linear = info_node->info_linear; 61 62 for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) { 63 u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms); 64 u64 addr = addrs[i]; 65 struct map *map = maps__find(machine__kernel_maps(machine), addr); 66 67 if (map) { 68 struct dso *dso = map__dso(map); 69 70 dso__set_binary_type(dso, DSO_BINARY_TYPE__BPF_PROG_INFO); 71 dso__bpf_prog(dso)->id = id; 72 dso__bpf_prog(dso)->sub_id = i; 73 dso__bpf_prog(dso)->env = env; 74 map__put(map); 75 } 76 } 77 return 0; 78 } 79 80 int machine__process_bpf(struct machine *machine, union perf_event *event, 81 struct perf_sample *sample) 82 { 83 if (dump_trace) 84 perf_event__fprintf_bpf(event, stdout); 85 86 switch (event->bpf.type) { 87 case PERF_BPF_EVENT_PROG_LOAD: 88 return machine__process_bpf_event_load(machine, event, sample); 89 90 case PERF_BPF_EVENT_PROG_UNLOAD: 91 /* 92 * Do not free bpf_prog_info and btf of the program here, 93 * as annotation still need them. They will be freed at 94 * the end of the session. 95 */ 96 break; 97 default: 98 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 99 break; 100 } 101 return 0; 102 } 103 104 static int perf_env__fetch_btf(struct perf_env *env, 105 u32 btf_id, 106 struct btf *btf) 107 { 108 struct btf_node *node; 109 u32 data_size; 110 const void *data; 111 112 data = btf__raw_data(btf, &data_size); 113 114 node = malloc(data_size + sizeof(struct btf_node)); 115 if (!node) 116 return -1; 117 118 node->id = btf_id; 119 node->data_size = data_size; 120 memcpy(node->data, data, data_size); 121 122 if (!perf_env__insert_btf(env, node)) { 123 /* Insertion failed because of a duplicate. */ 124 free(node); 125 return -1; 126 } 127 return 0; 128 } 129 130 static int synthesize_bpf_prog_name(char *buf, int size, 131 struct bpf_prog_info *info, 132 struct btf *btf, 133 u32 sub_id) 134 { 135 u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags); 136 void *func_infos = (void *)(uintptr_t)(info->func_info); 137 u32 sub_prog_cnt = info->nr_jited_ksyms; 138 const struct bpf_func_info *finfo; 139 const char *short_name = NULL; 140 const struct btf_type *t; 141 int name_len; 142 143 name_len = snprintf(buf, size, "bpf_prog_"); 144 name_len += snprintf_hex(buf + name_len, size - name_len, 145 prog_tags[sub_id], BPF_TAG_SIZE); 146 if (btf) { 147 finfo = func_infos + sub_id * info->func_info_rec_size; 148 t = btf__type_by_id(btf, finfo->type_id); 149 short_name = btf__name_by_offset(btf, t->name_off); 150 } else if (sub_id == 0 && sub_prog_cnt == 1) { 151 /* no subprog */ 152 if (info->name[0]) 153 short_name = info->name; 154 } else 155 short_name = "F"; 156 if (short_name) 157 name_len += snprintf(buf + name_len, size - name_len, 158 "_%s", short_name); 159 return name_len; 160 } 161 162 #ifdef HAVE_LIBBPF_STRINGS_SUPPORT 163 164 #define BPF_METADATA_PREFIX "bpf_metadata_" 165 #define BPF_METADATA_PREFIX_LEN (sizeof(BPF_METADATA_PREFIX) - 1) 166 167 static bool name_has_bpf_metadata_prefix(const char **s) 168 { 169 if (strncmp(*s, BPF_METADATA_PREFIX, BPF_METADATA_PREFIX_LEN) != 0) 170 return false; 171 *s += BPF_METADATA_PREFIX_LEN; 172 return true; 173 } 174 175 struct bpf_metadata_map { 176 struct btf *btf; 177 const struct btf_type *datasec; 178 void *rodata; 179 size_t rodata_size; 180 unsigned int num_vars; 181 }; 182 183 static int bpf_metadata_read_map_data(__u32 map_id, struct bpf_metadata_map *map) 184 { 185 int map_fd; 186 struct bpf_map_info map_info; 187 __u32 map_info_len; 188 int key; 189 struct btf *btf; 190 const struct btf_type *datasec; 191 struct btf_var_secinfo *vsi; 192 unsigned int vlen, vars; 193 void *rodata; 194 195 map_fd = bpf_map_get_fd_by_id(map_id); 196 if (map_fd < 0) 197 return -1; 198 199 memset(&map_info, 0, sizeof(map_info)); 200 map_info_len = sizeof(map_info); 201 if (bpf_obj_get_info_by_fd(map_fd, &map_info, &map_info_len) < 0) 202 goto out_close; 203 204 /* If it's not an .rodata map, don't bother. */ 205 if (map_info.type != BPF_MAP_TYPE_ARRAY || 206 map_info.key_size != sizeof(int) || 207 map_info.max_entries != 1 || 208 !map_info.btf_value_type_id || 209 !strstr(map_info.name, ".rodata")) { 210 goto out_close; 211 } 212 213 btf = btf__load_from_kernel_by_id(map_info.btf_id); 214 if (!btf) 215 goto out_close; 216 datasec = btf__type_by_id(btf, map_info.btf_value_type_id); 217 if (!btf_is_datasec(datasec)) 218 goto out_free_btf; 219 220 /* 221 * If there aren't any variables with the "bpf_metadata_" prefix, 222 * don't bother. 223 */ 224 vlen = btf_vlen(datasec); 225 vsi = btf_var_secinfos(datasec); 226 vars = 0; 227 for (unsigned int i = 0; i < vlen; i++, vsi++) { 228 const struct btf_type *t_var = btf__type_by_id(btf, vsi->type); 229 const char *name = btf__name_by_offset(btf, t_var->name_off); 230 231 if (name_has_bpf_metadata_prefix(&name)) 232 vars++; 233 } 234 if (vars == 0) 235 goto out_free_btf; 236 237 rodata = zalloc(map_info.value_size); 238 if (!rodata) 239 goto out_free_btf; 240 key = 0; 241 if (bpf_map_lookup_elem(map_fd, &key, rodata)) { 242 free(rodata); 243 goto out_free_btf; 244 } 245 close(map_fd); 246 247 map->btf = btf; 248 map->datasec = datasec; 249 map->rodata = rodata; 250 map->rodata_size = map_info.value_size; 251 map->num_vars = vars; 252 return 0; 253 254 out_free_btf: 255 btf__free(btf); 256 out_close: 257 close(map_fd); 258 return -1; 259 } 260 261 struct format_btf_ctx { 262 char *buf; 263 size_t buf_size; 264 size_t buf_idx; 265 }; 266 267 static void format_btf_cb(void *arg, const char *fmt, va_list ap) 268 { 269 int n; 270 struct format_btf_ctx *ctx = (struct format_btf_ctx *)arg; 271 272 n = vsnprintf(ctx->buf + ctx->buf_idx, ctx->buf_size - ctx->buf_idx, 273 fmt, ap); 274 ctx->buf_idx += n; 275 if (ctx->buf_idx >= ctx->buf_size) 276 ctx->buf_idx = ctx->buf_size; 277 } 278 279 static void format_btf_variable(struct btf *btf, char *buf, size_t buf_size, 280 const struct btf_type *t, const void *btf_data) 281 { 282 struct format_btf_ctx ctx = { 283 .buf = buf, 284 .buf_idx = 0, 285 .buf_size = buf_size, 286 }; 287 const struct btf_dump_type_data_opts opts = { 288 .sz = sizeof(struct btf_dump_type_data_opts), 289 .skip_names = 1, 290 .compact = 1, 291 .emit_strings = 1, 292 }; 293 struct btf_dump *d; 294 size_t btf_size; 295 296 d = btf_dump__new(btf, format_btf_cb, &ctx, NULL); 297 btf_size = btf__resolve_size(btf, t->type); 298 btf_dump__dump_type_data(d, t->type, btf_data, btf_size, &opts); 299 btf_dump__free(d); 300 } 301 302 static void bpf_metadata_fill_event(struct bpf_metadata_map *map, 303 struct perf_record_bpf_metadata *bpf_metadata_event) 304 { 305 struct btf_var_secinfo *vsi; 306 unsigned int i, vlen; 307 308 memset(bpf_metadata_event->prog_name, 0, BPF_PROG_NAME_LEN); 309 vlen = btf_vlen(map->datasec); 310 vsi = btf_var_secinfos(map->datasec); 311 312 for (i = 0; i < vlen; i++, vsi++) { 313 const struct btf_type *t_var = btf__type_by_id(map->btf, 314 vsi->type); 315 const char *name = btf__name_by_offset(map->btf, 316 t_var->name_off); 317 const __u64 nr_entries = bpf_metadata_event->nr_entries; 318 struct perf_record_bpf_metadata_entry *entry; 319 320 if (!name_has_bpf_metadata_prefix(&name)) 321 continue; 322 323 if (nr_entries >= (__u64)map->num_vars) 324 break; 325 326 entry = &bpf_metadata_event->entries[nr_entries]; 327 memset(entry, 0, sizeof(*entry)); 328 snprintf(entry->key, BPF_METADATA_KEY_LEN, "%s", name); 329 format_btf_variable(map->btf, entry->value, 330 BPF_METADATA_VALUE_LEN, t_var, 331 map->rodata + vsi->offset); 332 bpf_metadata_event->nr_entries++; 333 } 334 } 335 336 static void bpf_metadata_free_map_data(struct bpf_metadata_map *map) 337 { 338 btf__free(map->btf); 339 free(map->rodata); 340 } 341 342 static struct bpf_metadata *bpf_metadata_alloc(__u32 nr_prog_tags, 343 __u32 nr_variables) 344 { 345 struct bpf_metadata *metadata; 346 size_t event_size; 347 348 metadata = zalloc(sizeof(struct bpf_metadata)); 349 if (!metadata) 350 return NULL; 351 352 metadata->prog_names = zalloc(nr_prog_tags * sizeof(char *)); 353 if (!metadata->prog_names) { 354 bpf_metadata_free(metadata); 355 return NULL; 356 } 357 for (__u32 prog_index = 0; prog_index < nr_prog_tags; prog_index++) { 358 metadata->prog_names[prog_index] = zalloc(BPF_PROG_NAME_LEN); 359 if (!metadata->prog_names[prog_index]) { 360 bpf_metadata_free(metadata); 361 return NULL; 362 } 363 metadata->nr_prog_names++; 364 } 365 366 event_size = sizeof(metadata->event->bpf_metadata) + 367 nr_variables * sizeof(metadata->event->bpf_metadata.entries[0]); 368 metadata->event = zalloc(event_size); 369 if (!metadata->event) { 370 bpf_metadata_free(metadata); 371 return NULL; 372 } 373 metadata->event->bpf_metadata = (struct perf_record_bpf_metadata) { 374 .header = { 375 .type = PERF_RECORD_BPF_METADATA, 376 .size = event_size, 377 }, 378 .nr_entries = 0, 379 }; 380 381 return metadata; 382 } 383 384 static struct bpf_metadata *bpf_metadata_create(struct bpf_prog_info *info) 385 { 386 struct bpf_metadata *metadata; 387 const __u32 *map_ids = (__u32 *)(uintptr_t)info->map_ids; 388 389 for (__u32 map_index = 0; map_index < info->nr_map_ids; map_index++) { 390 struct bpf_metadata_map map; 391 392 if (bpf_metadata_read_map_data(map_ids[map_index], &map) != 0) 393 continue; 394 395 metadata = bpf_metadata_alloc(info->nr_prog_tags, map.num_vars); 396 if (!metadata) 397 continue; 398 399 bpf_metadata_fill_event(&map, &metadata->event->bpf_metadata); 400 401 for (__u32 index = 0; index < info->nr_prog_tags; index++) { 402 synthesize_bpf_prog_name(metadata->prog_names[index], 403 BPF_PROG_NAME_LEN, info, 404 map.btf, index); 405 } 406 407 bpf_metadata_free_map_data(&map); 408 409 return metadata; 410 } 411 412 return NULL; 413 } 414 415 static int synthesize_perf_record_bpf_metadata(const struct bpf_metadata *metadata, 416 const struct perf_tool *tool, 417 perf_event__handler_t process, 418 struct machine *machine) 419 { 420 const size_t event_size = metadata->event->header.size; 421 union perf_event *event; 422 int err = 0; 423 424 event = zalloc(event_size + machine->id_hdr_size); 425 if (!event) 426 return -1; 427 memcpy(event, metadata->event, event_size); 428 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 429 event->header.size += machine->id_hdr_size; 430 for (__u32 index = 0; index < metadata->nr_prog_names; index++) { 431 memcpy(event->bpf_metadata.prog_name, 432 metadata->prog_names[index], BPF_PROG_NAME_LEN); 433 err = perf_tool__process_synth_event(tool, event, machine, 434 process); 435 if (err != 0) 436 break; 437 } 438 439 free(event); 440 return err; 441 } 442 443 void bpf_metadata_free(struct bpf_metadata *metadata) 444 { 445 if (metadata == NULL) 446 return; 447 for (__u32 index = 0; index < metadata->nr_prog_names; index++) 448 free(metadata->prog_names[index]); 449 free(metadata->prog_names); 450 free(metadata->event); 451 free(metadata); 452 } 453 454 #else /* HAVE_LIBBPF_STRINGS_SUPPORT */ 455 456 static struct bpf_metadata *bpf_metadata_create(struct bpf_prog_info *info __maybe_unused) 457 { 458 return NULL; 459 } 460 461 static int synthesize_perf_record_bpf_metadata(const struct bpf_metadata *metadata __maybe_unused, 462 const struct perf_tool *tool __maybe_unused, 463 perf_event__handler_t process __maybe_unused, 464 struct machine *machine __maybe_unused) 465 { 466 return 0; 467 } 468 469 void bpf_metadata_free(struct bpf_metadata *metadata __maybe_unused) 470 { 471 } 472 473 #endif /* HAVE_LIBBPF_STRINGS_SUPPORT */ 474 475 struct bpf_metadata_final_ctx { 476 const struct perf_tool *tool; 477 perf_event__handler_t process; 478 struct machine *machine; 479 }; 480 481 static void synthesize_final_bpf_metadata_cb(struct bpf_prog_info_node *node, 482 void *data) 483 { 484 struct bpf_metadata_final_ctx *ctx = (struct bpf_metadata_final_ctx *)data; 485 struct bpf_metadata *metadata = node->metadata; 486 int err; 487 488 if (metadata == NULL) 489 return; 490 err = synthesize_perf_record_bpf_metadata(metadata, ctx->tool, 491 ctx->process, ctx->machine); 492 if (err != 0) { 493 const char *prog_name = metadata->prog_names[0]; 494 495 if (prog_name != NULL) 496 pr_warning("Couldn't synthesize final BPF metadata for %s.\n", prog_name); 497 else 498 pr_warning("Couldn't synthesize final BPF metadata.\n"); 499 } 500 bpf_metadata_free(metadata); 501 node->metadata = NULL; 502 } 503 504 void perf_event__synthesize_final_bpf_metadata(struct perf_session *session, 505 perf_event__handler_t process) 506 { 507 struct perf_env *env = &session->header.env; 508 struct bpf_metadata_final_ctx ctx = { 509 .tool = session->tool, 510 .process = process, 511 .machine = &session->machines.host, 512 }; 513 514 perf_env__iterate_bpf_prog_info(env, synthesize_final_bpf_metadata_cb, 515 &ctx); 516 } 517 518 /* 519 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf 520 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And 521 * one PERF_RECORD_KSYMBOL is generated for each sub program. 522 * 523 * Returns: 524 * 0 for success; 525 * -1 for failures; 526 * -2 for lack of kernel support. 527 */ 528 static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, 529 perf_event__handler_t process, 530 struct machine *machine, 531 int fd, 532 union perf_event *event, 533 struct record_opts *opts) 534 { 535 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol; 536 struct perf_record_bpf_event *bpf_event = &event->bpf; 537 const struct perf_tool *tool = session->tool; 538 struct bpf_prog_info_node *info_node; 539 struct perf_bpil *info_linear; 540 struct bpf_metadata *metadata; 541 struct bpf_prog_info *info; 542 struct btf *btf = NULL; 543 struct perf_env *env; 544 u32 sub_prog_cnt, i; 545 int err = 0; 546 u64 arrays; 547 548 /* 549 * for perf-record and perf-report use header.env; 550 * otherwise, use global perf_env. 551 */ 552 env = perf_session__env(session); 553 554 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 555 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 556 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 557 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 558 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 559 arrays |= 1UL << PERF_BPIL_LINE_INFO; 560 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 561 arrays |= 1UL << PERF_BPIL_MAP_IDS; 562 563 info_linear = get_bpf_prog_info_linear(fd, arrays); 564 if (IS_ERR_OR_NULL(info_linear)) { 565 info_linear = NULL; 566 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 567 return -1; 568 } 569 570 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { 571 free(info_linear); 572 pr_debug("%s: the kernel is too old, aborting\n", __func__); 573 return -2; 574 } 575 576 info = &info_linear->info; 577 if (!info->jited_ksyms) { 578 free(info_linear); 579 return -1; 580 } 581 582 /* number of ksyms, func_lengths, and tags should match */ 583 sub_prog_cnt = info->nr_jited_ksyms; 584 if (sub_prog_cnt != info->nr_prog_tags || 585 sub_prog_cnt != info->nr_jited_func_lens) { 586 free(info_linear); 587 return -1; 588 } 589 590 /* check BTF func info support */ 591 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { 592 /* btf func info number should be same as sub_prog_cnt */ 593 if (sub_prog_cnt != info->nr_func_info) { 594 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); 595 free(info_linear); 596 return -1; 597 } 598 btf = btf__load_from_kernel_by_id(info->btf_id); 599 if (libbpf_get_error(btf)) { 600 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id); 601 err = -1; 602 goto out; 603 } 604 perf_env__fetch_btf(env, info->btf_id, btf); 605 } 606 607 /* Synthesize PERF_RECORD_KSYMBOL */ 608 for (i = 0; i < sub_prog_cnt; i++) { 609 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 610 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 611 int name_len; 612 613 *ksymbol_event = (struct perf_record_ksymbol) { 614 .header = { 615 .type = PERF_RECORD_KSYMBOL, 616 .size = offsetof(struct perf_record_ksymbol, name), 617 }, 618 .addr = prog_addrs[i], 619 .len = prog_lens[i], 620 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 621 .flags = 0, 622 }; 623 624 name_len = synthesize_bpf_prog_name(ksymbol_event->name, 625 KSYM_NAME_LEN, info, btf, i); 626 ksymbol_event->header.size += PERF_ALIGN(name_len + 1, 627 sizeof(u64)); 628 629 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 630 event->header.size += machine->id_hdr_size; 631 err = perf_tool__process_synth_event(tool, event, 632 machine, process); 633 } 634 635 if (!opts->no_bpf_event) { 636 /* Synthesize PERF_RECORD_BPF_EVENT */ 637 *bpf_event = (struct perf_record_bpf_event) { 638 .header = { 639 .type = PERF_RECORD_BPF_EVENT, 640 .size = sizeof(struct perf_record_bpf_event), 641 }, 642 .type = PERF_BPF_EVENT_PROG_LOAD, 643 .flags = 0, 644 .id = info->id, 645 }; 646 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE); 647 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 648 event->header.size += machine->id_hdr_size; 649 650 /* save bpf_prog_info to env */ 651 info_node = malloc(sizeof(struct bpf_prog_info_node)); 652 if (!info_node) { 653 err = -1; 654 goto out; 655 } 656 657 info_node->info_linear = info_linear; 658 info_node->metadata = NULL; 659 if (!perf_env__insert_bpf_prog_info(env, info_node)) { 660 free(info_linear); 661 free(info_node); 662 } 663 info_linear = NULL; 664 665 /* 666 * process after saving bpf_prog_info to env, so that 667 * required information is ready for look up 668 */ 669 err = perf_tool__process_synth_event(tool, event, 670 machine, process); 671 672 /* Synthesize PERF_RECORD_BPF_METADATA */ 673 metadata = bpf_metadata_create(info); 674 if (metadata != NULL) { 675 err = synthesize_perf_record_bpf_metadata(metadata, 676 tool, process, 677 machine); 678 bpf_metadata_free(metadata); 679 } 680 } 681 682 out: 683 free(info_linear); 684 btf__free(btf); 685 return err ? -1 : 0; 686 } 687 688 struct kallsyms_parse { 689 union perf_event *event; 690 perf_event__handler_t process; 691 struct machine *machine; 692 const struct perf_tool *tool; 693 }; 694 695 static int 696 process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data) 697 { 698 struct machine *machine = data->machine; 699 union perf_event *event = data->event; 700 struct perf_record_ksymbol *ksymbol; 701 int len; 702 703 ksymbol = &event->ksymbol; 704 705 *ksymbol = (struct perf_record_ksymbol) { 706 .header = { 707 .type = PERF_RECORD_KSYMBOL, 708 .size = offsetof(struct perf_record_ksymbol, name), 709 }, 710 .addr = addr, 711 .len = page_size, 712 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 713 .flags = 0, 714 }; 715 716 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name); 717 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64)); 718 memset((void *) event + event->header.size, 0, machine->id_hdr_size); 719 event->header.size += machine->id_hdr_size; 720 721 return perf_tool__process_synth_event(data->tool, event, machine, 722 data->process); 723 } 724 725 static int 726 kallsyms_process_symbol(void *data, const char *_name, 727 char type __maybe_unused, u64 start) 728 { 729 char disp[KSYM_NAME_LEN]; 730 char *module, *name; 731 unsigned long id; 732 int err = 0; 733 734 module = strchr(_name, '\t'); 735 if (!module) 736 return 0; 737 738 /* We are going after [bpf] module ... */ 739 if (strcmp(module + 1, "[bpf]")) 740 return 0; 741 742 name = memdup(_name, (module - _name) + 1); 743 if (!name) 744 return -ENOMEM; 745 746 name[module - _name] = 0; 747 748 /* .. and only for trampolines and dispatchers */ 749 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) || 750 (sscanf(name, "bpf_dispatcher_%s", disp) == 1)) 751 err = process_bpf_image(name, start, data); 752 753 free(name); 754 return err; 755 } 756 757 int perf_event__synthesize_bpf_events(struct perf_session *session, 758 perf_event__handler_t process, 759 struct machine *machine, 760 struct record_opts *opts) 761 { 762 const char *kallsyms_filename = "/proc/kallsyms"; 763 struct kallsyms_parse arg; 764 union perf_event *event; 765 __u32 id = 0; 766 int err; 767 int fd; 768 769 if (opts->no_bpf_event) 770 return 0; 771 772 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); 773 if (!event) 774 return -1; 775 776 /* Synthesize all the bpf programs in system. */ 777 while (true) { 778 err = bpf_prog_get_next_id(id, &id); 779 if (err) { 780 if (errno == ENOENT) { 781 err = 0; 782 break; 783 } 784 pr_debug("%s: can't get next program: %s%s\n", 785 __func__, strerror(errno), 786 errno == EINVAL ? " -- kernel too old?" : ""); 787 /* don't report error on old kernel or EPERM */ 788 err = (errno == EINVAL || errno == EPERM) ? 0 : -1; 789 break; 790 } 791 fd = bpf_prog_get_fd_by_id(id); 792 if (fd < 0) { 793 pr_debug("%s: failed to get fd for prog_id %u\n", 794 __func__, id); 795 continue; 796 } 797 798 err = perf_event__synthesize_one_bpf_prog(session, process, 799 machine, fd, 800 event, opts); 801 close(fd); 802 if (err) { 803 /* do not return error for old kernel */ 804 if (err == -2) 805 err = 0; 806 break; 807 } 808 } 809 810 /* Synthesize all the bpf images - trampolines/dispatchers. */ 811 if (symbol_conf.kallsyms_name != NULL) 812 kallsyms_filename = symbol_conf.kallsyms_name; 813 814 arg = (struct kallsyms_parse) { 815 .event = event, 816 .process = process, 817 .machine = machine, 818 .tool = session->tool, 819 }; 820 821 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) { 822 pr_err("%s: failed to synthesize bpf images: %s\n", 823 __func__, strerror(errno)); 824 } 825 826 free(event); 827 return err; 828 } 829 830 static void perf_env__add_bpf_info(struct perf_env *env, u32 id) 831 { 832 struct bpf_prog_info_node *info_node; 833 struct perf_bpil *info_linear; 834 struct btf *btf = NULL; 835 u64 arrays; 836 u32 btf_id; 837 int fd; 838 839 fd = bpf_prog_get_fd_by_id(id); 840 if (fd < 0) 841 return; 842 843 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 844 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 845 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 846 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 847 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 848 arrays |= 1UL << PERF_BPIL_LINE_INFO; 849 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 850 arrays |= 1UL << PERF_BPIL_MAP_IDS; 851 852 info_linear = get_bpf_prog_info_linear(fd, arrays); 853 if (IS_ERR_OR_NULL(info_linear)) { 854 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 855 goto out; 856 } 857 858 btf_id = info_linear->info.btf_id; 859 860 info_node = malloc(sizeof(struct bpf_prog_info_node)); 861 if (info_node) { 862 info_node->info_linear = info_linear; 863 info_node->metadata = bpf_metadata_create(&info_linear->info); 864 if (!perf_env__insert_bpf_prog_info(env, info_node)) { 865 free(info_linear); 866 free(info_node); 867 } 868 } else 869 free(info_linear); 870 871 if (btf_id == 0) 872 goto out; 873 874 btf = btf__load_from_kernel_by_id(btf_id); 875 if (libbpf_get_error(btf)) { 876 pr_debug("%s: failed to get BTF of id %u, aborting\n", 877 __func__, btf_id); 878 goto out; 879 } 880 perf_env__fetch_btf(env, btf_id, btf); 881 882 out: 883 btf__free(btf); 884 close(fd); 885 } 886 887 static int bpf_event__sb_cb(union perf_event *event, void *data) 888 { 889 struct perf_env *env = data; 890 891 if (event->header.type != PERF_RECORD_BPF_EVENT) 892 return -1; 893 894 switch (event->bpf.type) { 895 case PERF_BPF_EVENT_PROG_LOAD: 896 perf_env__add_bpf_info(env, event->bpf.id); 897 898 case PERF_BPF_EVENT_PROG_UNLOAD: 899 /* 900 * Do not free bpf_prog_info and btf of the program here, 901 * as annotation still need them. They will be freed at 902 * the end of the session. 903 */ 904 break; 905 default: 906 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 907 break; 908 } 909 910 return 0; 911 } 912 913 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) 914 { 915 struct perf_event_attr attr = { 916 .type = PERF_TYPE_SOFTWARE, 917 .config = PERF_COUNT_SW_DUMMY, 918 .sample_id_all = 1, 919 .watermark = 1, 920 .bpf_event = 1, 921 .size = sizeof(attr), /* to capture ABI version */ 922 }; 923 924 /* 925 * Older gcc versions don't support designated initializers, like above, 926 * for unnamed union members, such as the following: 927 */ 928 attr.wakeup_watermark = 1; 929 930 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); 931 } 932 933 void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, 934 struct perf_env *env, 935 FILE *fp) 936 { 937 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 938 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 939 char name[KSYM_NAME_LEN]; 940 struct btf *btf = NULL; 941 u32 sub_prog_cnt, i; 942 943 sub_prog_cnt = info->nr_jited_ksyms; 944 if (sub_prog_cnt != info->nr_prog_tags || 945 sub_prog_cnt != info->nr_jited_func_lens) 946 return; 947 948 if (info->btf_id) { 949 struct btf_node *node; 950 951 node = __perf_env__find_btf(env, info->btf_id); 952 if (node) 953 btf = btf__new((__u8 *)(node->data), 954 node->data_size); 955 } 956 957 if (sub_prog_cnt == 1) { 958 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0); 959 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n", 960 info->id, name, prog_addrs[0], prog_lens[0]); 961 goto out; 962 } 963 964 fprintf(fp, "# bpf_prog_info %u:\n", info->id); 965 for (i = 0; i < sub_prog_cnt; i++) { 966 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i); 967 968 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n", 969 i, name, prog_addrs[i], prog_lens[i]); 970 } 971 out: 972 btf__free(btf); 973 } 974