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