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