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 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 perf_env__insert_bpf_prog_info(env, info_node); 293 info_linear = NULL; 294 295 /* 296 * process after saving bpf_prog_info to env, so that 297 * required information is ready for look up 298 */ 299 err = perf_tool__process_synth_event(tool, event, 300 machine, process); 301 } 302 303 out: 304 free(info_linear); 305 btf__free(btf); 306 return err ? -1 : 0; 307 } 308 309 struct kallsyms_parse { 310 union perf_event *event; 311 perf_event__handler_t process; 312 struct machine *machine; 313 struct perf_tool *tool; 314 }; 315 316 static int 317 process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data) 318 { 319 struct machine *machine = data->machine; 320 union perf_event *event = data->event; 321 struct perf_record_ksymbol *ksymbol; 322 int len; 323 324 ksymbol = &event->ksymbol; 325 326 *ksymbol = (struct perf_record_ksymbol) { 327 .header = { 328 .type = PERF_RECORD_KSYMBOL, 329 .size = offsetof(struct perf_record_ksymbol, name), 330 }, 331 .addr = addr, 332 .len = page_size, 333 .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, 334 .flags = 0, 335 }; 336 337 len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name); 338 ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64)); 339 memset((void *) event + event->header.size, 0, machine->id_hdr_size); 340 event->header.size += machine->id_hdr_size; 341 342 return perf_tool__process_synth_event(data->tool, event, machine, 343 data->process); 344 } 345 346 static int 347 kallsyms_process_symbol(void *data, const char *_name, 348 char type __maybe_unused, u64 start) 349 { 350 char disp[KSYM_NAME_LEN]; 351 char *module, *name; 352 unsigned long id; 353 int err = 0; 354 355 module = strchr(_name, '\t'); 356 if (!module) 357 return 0; 358 359 /* We are going after [bpf] module ... */ 360 if (strcmp(module + 1, "[bpf]")) 361 return 0; 362 363 name = memdup(_name, (module - _name) + 1); 364 if (!name) 365 return -ENOMEM; 366 367 name[module - _name] = 0; 368 369 /* .. and only for trampolines and dispatchers */ 370 if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) || 371 (sscanf(name, "bpf_dispatcher_%s", disp) == 1)) 372 err = process_bpf_image(name, start, data); 373 374 free(name); 375 return err; 376 } 377 378 int perf_event__synthesize_bpf_events(struct perf_session *session, 379 perf_event__handler_t process, 380 struct machine *machine, 381 struct record_opts *opts) 382 { 383 const char *kallsyms_filename = "/proc/kallsyms"; 384 struct kallsyms_parse arg; 385 union perf_event *event; 386 __u32 id = 0; 387 int err; 388 int fd; 389 390 if (opts->no_bpf_event) 391 return 0; 392 393 event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); 394 if (!event) 395 return -1; 396 397 /* Synthesize all the bpf programs in system. */ 398 while (true) { 399 err = bpf_prog_get_next_id(id, &id); 400 if (err) { 401 if (errno == ENOENT) { 402 err = 0; 403 break; 404 } 405 pr_debug("%s: can't get next program: %s%s\n", 406 __func__, strerror(errno), 407 errno == EINVAL ? " -- kernel too old?" : ""); 408 /* don't report error on old kernel or EPERM */ 409 err = (errno == EINVAL || errno == EPERM) ? 0 : -1; 410 break; 411 } 412 fd = bpf_prog_get_fd_by_id(id); 413 if (fd < 0) { 414 pr_debug("%s: failed to get fd for prog_id %u\n", 415 __func__, id); 416 continue; 417 } 418 419 err = perf_event__synthesize_one_bpf_prog(session, process, 420 machine, fd, 421 event, opts); 422 close(fd); 423 if (err) { 424 /* do not return error for old kernel */ 425 if (err == -2) 426 err = 0; 427 break; 428 } 429 } 430 431 /* Synthesize all the bpf images - trampolines/dispatchers. */ 432 if (symbol_conf.kallsyms_name != NULL) 433 kallsyms_filename = symbol_conf.kallsyms_name; 434 435 arg = (struct kallsyms_parse) { 436 .event = event, 437 .process = process, 438 .machine = machine, 439 .tool = session->tool, 440 }; 441 442 if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) { 443 pr_err("%s: failed to synthesize bpf images: %s\n", 444 __func__, strerror(errno)); 445 } 446 447 free(event); 448 return err; 449 } 450 451 static void perf_env__add_bpf_info(struct perf_env *env, u32 id) 452 { 453 struct bpf_prog_info_node *info_node; 454 struct perf_bpil *info_linear; 455 struct btf *btf = NULL; 456 u64 arrays; 457 u32 btf_id; 458 int fd; 459 460 fd = bpf_prog_get_fd_by_id(id); 461 if (fd < 0) 462 return; 463 464 arrays = 1UL << PERF_BPIL_JITED_KSYMS; 465 arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS; 466 arrays |= 1UL << PERF_BPIL_FUNC_INFO; 467 arrays |= 1UL << PERF_BPIL_PROG_TAGS; 468 arrays |= 1UL << PERF_BPIL_JITED_INSNS; 469 arrays |= 1UL << PERF_BPIL_LINE_INFO; 470 arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO; 471 472 info_linear = get_bpf_prog_info_linear(fd, arrays); 473 if (IS_ERR_OR_NULL(info_linear)) { 474 pr_debug("%s: failed to get BPF program info. aborting\n", __func__); 475 goto out; 476 } 477 478 btf_id = info_linear->info.btf_id; 479 480 info_node = malloc(sizeof(struct bpf_prog_info_node)); 481 if (info_node) { 482 info_node->info_linear = info_linear; 483 perf_env__insert_bpf_prog_info(env, info_node); 484 } else 485 free(info_linear); 486 487 if (btf_id == 0) 488 goto out; 489 490 btf = btf__load_from_kernel_by_id(btf_id); 491 if (libbpf_get_error(btf)) { 492 pr_debug("%s: failed to get BTF of id %u, aborting\n", 493 __func__, btf_id); 494 goto out; 495 } 496 perf_env__fetch_btf(env, btf_id, btf); 497 498 out: 499 btf__free(btf); 500 close(fd); 501 } 502 503 static int bpf_event__sb_cb(union perf_event *event, void *data) 504 { 505 struct perf_env *env = data; 506 507 if (event->header.type != PERF_RECORD_BPF_EVENT) 508 return -1; 509 510 switch (event->bpf.type) { 511 case PERF_BPF_EVENT_PROG_LOAD: 512 perf_env__add_bpf_info(env, event->bpf.id); 513 514 case PERF_BPF_EVENT_PROG_UNLOAD: 515 /* 516 * Do not free bpf_prog_info and btf of the program here, 517 * as annotation still need them. They will be freed at 518 * the end of the session. 519 */ 520 break; 521 default: 522 pr_debug("unexpected bpf event type of %d\n", event->bpf.type); 523 break; 524 } 525 526 return 0; 527 } 528 529 int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) 530 { 531 struct perf_event_attr attr = { 532 .type = PERF_TYPE_SOFTWARE, 533 .config = PERF_COUNT_SW_DUMMY, 534 .sample_id_all = 1, 535 .watermark = 1, 536 .bpf_event = 1, 537 .size = sizeof(attr), /* to capture ABI version */ 538 }; 539 540 /* 541 * Older gcc versions don't support designated initializers, like above, 542 * for unnamed union members, such as the following: 543 */ 544 attr.wakeup_watermark = 1; 545 546 return evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); 547 } 548 549 void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, 550 struct perf_env *env, 551 FILE *fp) 552 { 553 __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); 554 __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); 555 char name[KSYM_NAME_LEN]; 556 struct btf *btf = NULL; 557 u32 sub_prog_cnt, i; 558 559 sub_prog_cnt = info->nr_jited_ksyms; 560 if (sub_prog_cnt != info->nr_prog_tags || 561 sub_prog_cnt != info->nr_jited_func_lens) 562 return; 563 564 if (info->btf_id) { 565 struct btf_node *node; 566 567 node = __perf_env__find_btf(env, info->btf_id); 568 if (node) 569 btf = btf__new((__u8 *)(node->data), 570 node->data_size); 571 } 572 573 if (sub_prog_cnt == 1) { 574 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0); 575 fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n", 576 info->id, name, prog_addrs[0], prog_lens[0]); 577 goto out; 578 } 579 580 fprintf(fp, "# bpf_prog_info %u:\n", info->id); 581 for (i = 0; i < sub_prog_cnt; i++) { 582 synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i); 583 584 fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n", 585 i, name, prog_addrs[i], prog_lens[i]); 586 } 587 out: 588 btf__free(btf); 589 } 590