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 #if LIBBPF_CURRENT_VERSION_GEQ(1, 7) 292 .emit_strings = 1, 293 #endif 294 }; 295 struct btf_dump *d; 296 size_t btf_size; 297 298 d = btf_dump__new(btf, format_btf_cb, &ctx, NULL); 299 btf_size = btf__resolve_size(btf, t->type); 300 btf_dump__dump_type_data(d, t->type, btf_data, btf_size, &opts); 301 btf_dump__free(d); 302 } 303 304 static void bpf_metadata_fill_event(struct bpf_metadata_map *map, 305 struct perf_record_bpf_metadata *bpf_metadata_event) 306 { 307 struct btf_var_secinfo *vsi; 308 unsigned int i, vlen; 309 310 memset(bpf_metadata_event->prog_name, 0, BPF_PROG_NAME_LEN); 311 vlen = btf_vlen(map->datasec); 312 vsi = btf_var_secinfos(map->datasec); 313 314 for (i = 0; i < vlen; i++, vsi++) { 315 const struct btf_type *t_var = btf__type_by_id(map->btf, 316 vsi->type); 317 const char *name = btf__name_by_offset(map->btf, 318 t_var->name_off); 319 const __u64 nr_entries = bpf_metadata_event->nr_entries; 320 struct perf_record_bpf_metadata_entry *entry; 321 322 if (!name_has_bpf_metadata_prefix(&name)) 323 continue; 324 325 if (nr_entries >= (__u64)map->num_vars) 326 break; 327 328 entry = &bpf_metadata_event->entries[nr_entries]; 329 memset(entry, 0, sizeof(*entry)); 330 snprintf(entry->key, BPF_METADATA_KEY_LEN, "%s", name); 331 format_btf_variable(map->btf, entry->value, 332 BPF_METADATA_VALUE_LEN, t_var, 333 map->rodata + vsi->offset); 334 bpf_metadata_event->nr_entries++; 335 } 336 } 337 338 static void bpf_metadata_free_map_data(struct bpf_metadata_map *map) 339 { 340 btf__free(map->btf); 341 free(map->rodata); 342 } 343 344 static struct bpf_metadata *bpf_metadata_alloc(__u32 nr_prog_tags, 345 __u32 nr_variables) 346 { 347 struct bpf_metadata *metadata; 348 size_t event_size; 349 350 metadata = zalloc(sizeof(struct bpf_metadata)); 351 if (!metadata) 352 return NULL; 353 354 metadata->prog_names = zalloc(nr_prog_tags * sizeof(char *)); 355 if (!metadata->prog_names) { 356 bpf_metadata_free(metadata); 357 return NULL; 358 } 359 for (__u32 prog_index = 0; prog_index < nr_prog_tags; prog_index++) { 360 metadata->prog_names[prog_index] = zalloc(BPF_PROG_NAME_LEN); 361 if (!metadata->prog_names[prog_index]) { 362 bpf_metadata_free(metadata); 363 return NULL; 364 } 365 metadata->nr_prog_names++; 366 } 367 368 event_size = sizeof(metadata->event->bpf_metadata) + 369 nr_variables * sizeof(metadata->event->bpf_metadata.entries[0]); 370 metadata->event = zalloc(event_size); 371 if (!metadata->event) { 372 bpf_metadata_free(metadata); 373 return NULL; 374 } 375 metadata->event->bpf_metadata = (struct perf_record_bpf_metadata) { 376 .header = { 377 .type = PERF_RECORD_BPF_METADATA, 378 .size = event_size, 379 }, 380 .nr_entries = 0, 381 }; 382 383 return metadata; 384 } 385 386 static struct bpf_metadata *bpf_metadata_create(struct bpf_prog_info *info) 387 { 388 struct bpf_metadata *metadata; 389 const __u32 *map_ids = (__u32 *)(uintptr_t)info->map_ids; 390 391 for (__u32 map_index = 0; map_index < info->nr_map_ids; map_index++) { 392 struct bpf_metadata_map map; 393 394 if (bpf_metadata_read_map_data(map_ids[map_index], &map) != 0) 395 continue; 396 397 metadata = bpf_metadata_alloc(info->nr_prog_tags, map.num_vars); 398 if (!metadata) 399 continue; 400 401 bpf_metadata_fill_event(&map, &metadata->event->bpf_metadata); 402 403 for (__u32 index = 0; index < info->nr_prog_tags; index++) { 404 synthesize_bpf_prog_name(metadata->prog_names[index], 405 BPF_PROG_NAME_LEN, info, 406 map.btf, index); 407 } 408 409 bpf_metadata_free_map_data(&map); 410 411 return metadata; 412 } 413 414 return NULL; 415 } 416 417 static int synthesize_perf_record_bpf_metadata(const struct bpf_metadata *metadata, 418 const struct perf_tool *tool, 419 perf_event__handler_t process, 420 struct machine *machine) 421 { 422 const size_t event_size = metadata->event->header.size; 423 union perf_event *event; 424 int err = 0; 425 426 event = zalloc(event_size + machine->id_hdr_size); 427 if (!event) 428 return -1; 429 memcpy(event, metadata->event, event_size); 430 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 431 event->header.size += machine->id_hdr_size; 432 for (__u32 index = 0; index < metadata->nr_prog_names; index++) { 433 memcpy(event->bpf_metadata.prog_name, 434 metadata->prog_names[index], BPF_PROG_NAME_LEN); 435 err = perf_tool__process_synth_event(tool, event, machine, 436 process); 437 if (err != 0) 438 break; 439 } 440 441 free(event); 442 return err; 443 } 444 445 void bpf_metadata_free(struct bpf_metadata *metadata) 446 { 447 if (metadata == NULL) 448 return; 449 for (__u32 index = 0; index < metadata->nr_prog_names; index++) 450 free(metadata->prog_names[index]); 451 free(metadata->prog_names); 452 free(metadata->event); 453 free(metadata); 454 } 455 456 #else /* HAVE_LIBBPF_STRINGS_SUPPORT */ 457 458 static struct bpf_metadata *bpf_metadata_create(struct bpf_prog_info *info __maybe_unused) 459 { 460 return NULL; 461 } 462 463 static int synthesize_perf_record_bpf_metadata(const struct bpf_metadata *metadata __maybe_unused, 464 const struct perf_tool *tool __maybe_unused, 465 perf_event__handler_t process __maybe_unused, 466 struct machine *machine __maybe_unused) 467 { 468 return 0; 469 } 470 471 void bpf_metadata_free(struct bpf_metadata *metadata __maybe_unused) 472 { 473 } 474 475 #endif /* HAVE_LIBBPF_STRINGS_SUPPORT */ 476 477 struct bpf_metadata_final_ctx { 478 const struct perf_tool *tool; 479 perf_event__handler_t process; 480 struct machine *machine; 481 }; 482 483 static void synthesize_final_bpf_metadata_cb(struct bpf_prog_info_node *node, 484 void *data) 485 { 486 struct bpf_metadata_final_ctx *ctx = (struct bpf_metadata_final_ctx *)data; 487 struct bpf_metadata *metadata = node->metadata; 488 int err; 489 490 if (metadata == NULL) 491 return; 492 err = synthesize_perf_record_bpf_metadata(metadata, ctx->tool, 493 ctx->process, ctx->machine); 494 if (err != 0) { 495 const char *prog_name = metadata->prog_names[0]; 496 497 if (prog_name != NULL) 498 pr_warning("Couldn't synthesize final BPF metadata for %s.\n", prog_name); 499 else 500 pr_warning("Couldn't synthesize final BPF metadata.\n"); 501 } 502 bpf_metadata_free(metadata); 503 node->metadata = NULL; 504 } 505 506 void perf_event__synthesize_final_bpf_metadata(struct perf_session *session, 507 perf_event__handler_t process) 508 { 509 struct perf_env *env = &session->header.env; 510 struct bpf_metadata_final_ctx ctx = { 511 .tool = session->tool, 512 .process = process, 513 .machine = &session->machines.host, 514 }; 515 516 perf_env__iterate_bpf_prog_info(env, synthesize_final_bpf_metadata_cb, 517 &ctx); 518 } 519 520 /* 521 * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf 522 * program. One PERF_RECORD_BPF_EVENT is generated for the program. And 523 * one PERF_RECORD_KSYMBOL is generated for each sub program. 524 * 525 * Returns: 526 * 0 for success; 527 * -1 for failures; 528 * -2 for lack of kernel support. 529 */ 530 static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, 531 perf_event__handler_t process, 532 struct machine *machine, 533 int fd, 534 union perf_event *event, 535 struct record_opts *opts) 536 { 537 struct perf_record_ksymbol *ksymbol_event = &event->ksymbol; 538 struct perf_record_bpf_event *bpf_event = &event->bpf; 539 const struct perf_tool *tool = session->tool; 540 struct bpf_prog_info_node *info_node; 541 struct perf_bpil *info_linear; 542 struct bpf_metadata *metadata; 543 struct bpf_prog_info *info; 544 struct btf *btf = NULL; 545 struct perf_env *env; 546 u32 sub_prog_cnt, i; 547 int err = 0; 548 u64 arrays; 549 550 /* 551 * for perf-record and perf-report use header.env; 552 * otherwise, use global perf_env. 553 */ 554 env = perf_session__env(session); 555 556 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 557 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 558 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 559 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 560 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 561 arrays |= 1UL << PERF_BPIL_LINE_INFO; 562 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 563 arrays |= 1UL << PERF_BPIL_MAP_IDS; 564 565 info_linear = get_bpf_prog_info_linear(fd, arrays); 566 if (IS_ERR_OR_NULL(info_linear)) { 567 info_linear = NULL; 568 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 569 return -1; 570 } 571 572 if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { 573 free(info_linear); 574 pr_debug("%s: the kernel is too old, aborting\n", __func__); 575 return -2; 576 } 577 578 info = &info_linear->info; 579 if (!info->jited_ksyms) { 580 free(info_linear); 581 return -1; 582 } 583 584 /* number of ksyms, func_lengths, and tags should match */ 585 sub_prog_cnt = info->nr_jited_ksyms; 586 if (sub_prog_cnt != info->nr_prog_tags || 587 sub_prog_cnt != info->nr_jited_func_lens) { 588 free(info_linear); 589 return -1; 590 } 591 592 /* check BTF func info support */ 593 if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { 594 /* btf func info number should be same as sub_prog_cnt */ 595 if (sub_prog_cnt != info->nr_func_info) { 596 pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); 597 free(info_linear); 598 return -1; 599 } 600 btf = btf__load_from_kernel_by_id(info->btf_id); 601 if (libbpf_get_error(btf)) { 602 pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id); 603 err = -1; 604 goto out; 605 } 606 perf_env__fetch_btf(env, info->btf_id, btf); 607 } 608 609 /* Synthesize PERF_RECORD_KSYMBOL */ 610 for (i = 0; i < sub_prog_cnt; i++) { 611 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 612 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 613 int name_len; 614 615 *ksymbol_event = (struct perf_record_ksymbol) { 616 .header = { 617 .type = PERF_RECORD_KSYMBOL, 618 .size = offsetof(struct perf_record_ksymbol, name), 619 }, 620 .addr = prog_addrs[i], 621 .len = prog_lens[i], 622 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 623 .flags = 0, 624 }; 625 626 name_len = synthesize_bpf_prog_name(ksymbol_event->name, 627 KSYM_NAME_LEN, info, btf, i); 628 ksymbol_event->header.size += PERF_ALIGN(name_len + 1, 629 sizeof(u64)); 630 631 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 632 event->header.size += machine->id_hdr_size; 633 err = perf_tool__process_synth_event(tool, event, 634 machine, process); 635 } 636 637 if (!opts->no_bpf_event) { 638 /* Synthesize PERF_RECORD_BPF_EVENT */ 639 *bpf_event = (struct perf_record_bpf_event) { 640 .header = { 641 .type = PERF_RECORD_BPF_EVENT, 642 .size = sizeof(struct perf_record_bpf_event), 643 }, 644 .type = PERF_BPF_EVENT_PROG_LOAD, 645 .flags = 0, 646 .id = info->id, 647 }; 648 memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE); 649 memset((void *)event + event->header.size, 0, machine->id_hdr_size); 650 event->header.size += machine->id_hdr_size; 651 652 /* save bpf_prog_info to env */ 653 info_node = malloc(sizeof(struct bpf_prog_info_node)); 654 if (!info_node) { 655 err = -1; 656 goto out; 657 } 658 659 info_node->info_linear = info_linear; 660 info_node->metadata = NULL; 661 if (!perf_env__insert_bpf_prog_info(env, info_node)) { 662 /* 663 * Insert failed, likely because of a duplicate event 664 * made by the sideband thread. Ignore synthesizing the 665 * metadata. 666 */ 667 free(info_node); 668 goto out; 669 } 670 /* info_linear is now owned by info_node and shouldn't be freed below. */ 671 info_linear = NULL; 672 673 /* 674 * process after saving bpf_prog_info to env, so that 675 * required information is ready for look up 676 */ 677 err = perf_tool__process_synth_event(tool, event, 678 machine, process); 679 680 /* Synthesize PERF_RECORD_BPF_METADATA */ 681 metadata = bpf_metadata_create(info); 682 if (metadata != NULL) { 683 err = synthesize_perf_record_bpf_metadata(metadata, 684 tool, process, 685 machine); 686 bpf_metadata_free(metadata); 687 } 688 } 689 690 out: 691 free(info_linear); 692 btf__free(btf); 693 return err ? -1 : 0; 694 } 695 696 struct kallsyms_parse { 697 union perf_event *event; 698 perf_event__handler_t process; 699 struct machine *machine; 700 const struct perf_tool *tool; 701 }; 702 703 static int 704 process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data) 705 { 706 struct machine *machine = data->machine; 707 union perf_event *event = data->event; 708 struct perf_record_ksymbol *ksymbol; 709 int len; 710 711 ksymbol = &event->ksymbol; 712 713 *ksymbol = (struct perf_record_ksymbol) { 714 .header = { 715 .type = PERF_RECORD_KSYMBOL, 716 .size = offsetof(struct perf_record_ksymbol, name), 717 }, 718 .addr = addr, 719 .len = page_size, 720 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 721 .flags = 0, 722 }; 723 724 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name); 725 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64)); 726 memset((void *) event + event->header.size, 0, machine->id_hdr_size); 727 event->header.size += machine->id_hdr_size; 728 729 return perf_tool__process_synth_event(data->tool, event, machine, 730 data->process); 731 } 732 733 static int 734 kallsyms_process_symbol(void *data, const char *_name, 735 char type __maybe_unused, u64 start) 736 { 737 char disp[KSYM_NAME_LEN]; 738 char *module, *name; 739 unsigned long id; 740 int err = 0; 741 742 module = strchr(_name, '\t'); 743 if (!module) 744 return 0; 745 746 /* We are going after [bpf] module ... */ 747 if (strcmp(module + 1, "[bpf]")) 748 return 0; 749 750 name = memdup(_name, (module - _name) + 1); 751 if (!name) 752 return -ENOMEM; 753 754 name[module - _name] = 0; 755 756 /* .. and only for trampolines and dispatchers */ 757 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) || 758 (sscanf(name, "bpf_dispatcher_%s", disp) == 1)) 759 err = process_bpf_image(name, start, data); 760 761 free(name); 762 return err; 763 } 764 765 int perf_event__synthesize_bpf_events(struct perf_session *session, 766 perf_event__handler_t process, 767 struct machine *machine, 768 struct record_opts *opts) 769 { 770 const char *kallsyms_filename = "/proc/kallsyms"; 771 struct kallsyms_parse arg; 772 union perf_event *event; 773 __u32 id = 0; 774 int err; 775 int fd; 776 777 if (opts->no_bpf_event) 778 return 0; 779 780 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); 781 if (!event) 782 return -1; 783 784 /* Synthesize all the bpf programs in system. */ 785 while (true) { 786 err = bpf_prog_get_next_id(id, &id); 787 if (err) { 788 if (errno == ENOENT) { 789 err = 0; 790 break; 791 } 792 pr_debug("%s: can't get next program: %s%s\n", 793 __func__, strerror(errno), 794 errno == EINVAL ? " -- kernel too old?" : ""); 795 /* don't report error on old kernel or EPERM */ 796 err = (errno == EINVAL || errno == EPERM) ? 0 : -1; 797 break; 798 } 799 fd = bpf_prog_get_fd_by_id(id); 800 if (fd < 0) { 801 pr_debug("%s: failed to get fd for prog_id %u\n", 802 __func__, id); 803 continue; 804 } 805 806 err = perf_event__synthesize_one_bpf_prog(session, process, 807 machine, fd, 808 event, opts); 809 close(fd); 810 if (err) { 811 /* do not return error for old kernel */ 812 if (err == -2) 813 err = 0; 814 break; 815 } 816 } 817 818 /* Synthesize all the bpf images - trampolines/dispatchers. */ 819 if (symbol_conf.kallsyms_name != NULL) 820 kallsyms_filename = symbol_conf.kallsyms_name; 821 822 arg = (struct kallsyms_parse) { 823 .event = event, 824 .process = process, 825 .machine = machine, 826 .tool = session->tool, 827 }; 828 829 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) { 830 pr_err("%s: failed to synthesize bpf images: %s\n", 831 __func__, strerror(errno)); 832 } 833 834 free(event); 835 return err; 836 } 837 838 static int perf_env__add_bpf_info(struct perf_env *env, u32 id) 839 { 840 struct bpf_prog_info_node *info_node; 841 struct perf_bpil *info_linear; 842 struct btf *btf = NULL; 843 u64 arrays; 844 u32 btf_id; 845 int fd, err = 0; 846 847 fd = bpf_prog_get_fd_by_id(id); 848 if (fd < 0) 849 return -EINVAL; 850 851 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 852 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 853 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 854 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 855 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 856 arrays |= 1UL << PERF_BPIL_LINE_INFO; 857 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 858 arrays |= 1UL << PERF_BPIL_MAP_IDS; 859 860 info_linear = get_bpf_prog_info_linear(fd, arrays); 861 if (IS_ERR_OR_NULL(info_linear)) { 862 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 863 err = PTR_ERR(info_linear); 864 goto out; 865 } 866 867 btf_id = info_linear->info.btf_id; 868 869 info_node = malloc(sizeof(struct bpf_prog_info_node)); 870 if (info_node) { 871 info_node->info_linear = info_linear; 872 info_node->metadata = bpf_metadata_create(&info_linear->info); 873 if (!perf_env__insert_bpf_prog_info(env, info_node)) { 874 pr_debug("%s: duplicate add bpf info request for id %u\n", 875 __func__, btf_id); 876 free(info_linear); 877 free(info_node); 878 goto out; 879 } 880 } else { 881 free(info_linear); 882 err = -ENOMEM; 883 goto out; 884 } 885 886 if (btf_id == 0) 887 goto out; 888 889 btf = btf__load_from_kernel_by_id(btf_id); 890 if (!btf) { 891 err = -errno; 892 pr_debug("%s: failed to get BTF of id %u %d\n", __func__, btf_id, err); 893 } else { 894 perf_env__fetch_btf(env, btf_id, btf); 895 } 896 897 out: 898 btf__free(btf); 899 close(fd); 900 return err; 901 } 902 903 static int bpf_event__sb_cb(union perf_event *event, void *data) 904 { 905 struct perf_env *env = data; 906 int ret = 0; 907 908 if (event->header.type != PERF_RECORD_BPF_EVENT) 909 return -1; 910 911 switch (event->bpf.type) { 912 case PERF_BPF_EVENT_PROG_LOAD: 913 ret = perf_env__add_bpf_info(env, event->bpf.id); 914 915 case PERF_BPF_EVENT_PROG_UNLOAD: 916 /* 917 * Do not free bpf_prog_info and btf of the program here, 918 * as annotation still need them. They will be freed at 919 * the end of the session. 920 */ 921 break; 922 default: 923 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 924 break; 925 } 926 927 return ret; 928 } 929 930 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) 931 { 932 struct perf_event_attr attr = { 933 .type = PERF_TYPE_SOFTWARE, 934 .config = PERF_COUNT_SW_DUMMY, 935 .sample_id_all = 1, 936 .watermark = 1, 937 .bpf_event = 1, 938 .size = sizeof(attr), /* to capture ABI version */ 939 }; 940 941 /* 942 * Older gcc versions don't support designated initializers, like above, 943 * for unnamed union members, such as the following: 944 */ 945 attr.wakeup_watermark = 1; 946 947 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); 948 } 949 950 void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, 951 struct perf_env *env, 952 FILE *fp) 953 { 954 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 955 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 956 char name[KSYM_NAME_LEN]; 957 struct btf *btf = NULL; 958 u32 sub_prog_cnt, i; 959 960 sub_prog_cnt = info->nr_jited_ksyms; 961 if (sub_prog_cnt != info->nr_prog_tags || 962 sub_prog_cnt != info->nr_jited_func_lens) 963 return; 964 965 if (info->btf_id) { 966 struct btf_node *node; 967 968 node = __perf_env__find_btf(env, info->btf_id); 969 if (node) 970 btf = btf__new((__u8 *)(node->data), 971 node->data_size); 972 } 973 974 if (sub_prog_cnt == 1) { 975 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0); 976 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n", 977 info->id, name, prog_addrs[0], prog_lens[0]); 978 goto out; 979 } 980 981 fprintf(fp, "# bpf_prog_info %u:\n", info->id); 982 for (i = 0; i < sub_prog_cnt; i++) { 983 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i); 984 985 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n", 986 i, name, prog_addrs[i], prog_lens[i]); 987 } 988 out: 989 btf__free(btf); 990 } 991