1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * dlfilter.c: Interface to perf script --dlfilter shared object 4 * Copyright (c) 2021, Intel Corporation. 5 */ 6 #include <dlfcn.h> 7 #include <stdlib.h> 8 #include <string.h> 9 #include <dirent.h> 10 #include <subcmd/exec-cmd.h> 11 #include <linux/zalloc.h> 12 #include <linux/build_bug.h> 13 #include <linux/kernel.h> 14 #include <linux/string.h> 15 16 #include "debug.h" 17 #include "event.h" 18 #include "evsel.h" 19 #include "dso.h" 20 #include "map.h" 21 #include "thread.h" 22 #include "trace-event.h" 23 #include "symbol.h" 24 #include "srcline.h" 25 #include "dlfilter.h" 26 #include "../include/perf/perf_dlfilter.h" 27 28 static void al_to_d_al(struct addr_location *al, struct perf_dlfilter_al *d_al) 29 { 30 struct symbol *sym = al->sym; 31 32 d_al->size = sizeof(*d_al); 33 if (al->map) { 34 struct dso *dso = map__dso(al->map); 35 36 if (symbol_conf.show_kernel_path && dso->long_name) 37 d_al->dso = dso->long_name; 38 else 39 d_al->dso = dso->name; 40 d_al->is_64_bit = dso->is_64_bit; 41 d_al->buildid_size = dso->bid.size; 42 d_al->buildid = dso->bid.data; 43 } else { 44 d_al->dso = NULL; 45 d_al->is_64_bit = 0; 46 d_al->buildid_size = 0; 47 d_al->buildid = NULL; 48 } 49 if (sym) { 50 d_al->sym = sym->name; 51 d_al->sym_start = sym->start; 52 d_al->sym_end = sym->end; 53 if (al->addr < sym->end) 54 d_al->symoff = al->addr - sym->start; 55 else if (al->map) 56 d_al->symoff = al->addr - map__start(al->map) - sym->start; 57 else 58 d_al->symoff = 0; 59 d_al->sym_binding = sym->binding; 60 } else { 61 d_al->sym = NULL; 62 d_al->sym_start = 0; 63 d_al->sym_end = 0; 64 d_al->symoff = 0; 65 d_al->sym_binding = 0; 66 } 67 d_al->addr = al->addr; 68 d_al->comm = NULL; 69 d_al->filtered = 0; 70 d_al->priv = NULL; 71 } 72 73 static struct addr_location *get_al(struct dlfilter *d) 74 { 75 struct addr_location *al = d->al; 76 77 if (!al->thread && machine__resolve(d->machine, al, d->sample) < 0) 78 return NULL; 79 return al; 80 } 81 82 static struct thread *get_thread(struct dlfilter *d) 83 { 84 struct addr_location *al = get_al(d); 85 86 return al ? al->thread : NULL; 87 } 88 89 static const struct perf_dlfilter_al *dlfilter__resolve_ip(void *ctx) 90 { 91 struct dlfilter *d = (struct dlfilter *)ctx; 92 struct perf_dlfilter_al *d_al = d->d_ip_al; 93 struct addr_location *al; 94 95 if (!d->ctx_valid) 96 return NULL; 97 98 /* 'size' is also used to indicate already initialized */ 99 if (d_al->size) 100 return d_al; 101 102 al = get_al(d); 103 if (!al) 104 return NULL; 105 106 al_to_d_al(al, d_al); 107 108 d_al->is_kernel_ip = machine__kernel_ip(d->machine, d->sample->ip); 109 d_al->comm = al->thread ? thread__comm_str(al->thread) : ":-1"; 110 d_al->filtered = al->filtered; 111 112 return d_al; 113 } 114 115 static const struct perf_dlfilter_al *dlfilter__resolve_addr(void *ctx) 116 { 117 struct dlfilter *d = (struct dlfilter *)ctx; 118 struct perf_dlfilter_al *d_addr_al = d->d_addr_al; 119 struct addr_location *addr_al = d->addr_al; 120 121 if (!d->ctx_valid || !d->d_sample->addr_correlates_sym) 122 return NULL; 123 124 /* 'size' is also used to indicate already initialized */ 125 if (d_addr_al->size) 126 return d_addr_al; 127 128 if (!addr_al->thread) { 129 struct thread *thread = get_thread(d); 130 131 if (!thread) 132 return NULL; 133 thread__resolve(thread, addr_al, d->sample); 134 } 135 136 al_to_d_al(addr_al, d_addr_al); 137 138 d_addr_al->is_kernel_ip = machine__kernel_ip(d->machine, d->sample->addr); 139 140 return d_addr_al; 141 } 142 143 static char **dlfilter__args(void *ctx, int *dlargc) 144 { 145 struct dlfilter *d = (struct dlfilter *)ctx; 146 147 if (dlargc) 148 *dlargc = 0; 149 else 150 return NULL; 151 152 if (!d->ctx_valid && !d->in_start && !d->in_stop) 153 return NULL; 154 155 *dlargc = d->dlargc; 156 return d->dlargv; 157 } 158 159 static bool has_priv(struct perf_dlfilter_al *d_al_p) 160 { 161 return d_al_p->size >= offsetof(struct perf_dlfilter_al, priv) + sizeof(d_al_p->priv); 162 } 163 164 static __s32 dlfilter__resolve_address(void *ctx, __u64 address, struct perf_dlfilter_al *d_al_p) 165 { 166 struct dlfilter *d = (struct dlfilter *)ctx; 167 struct perf_dlfilter_al d_al; 168 struct addr_location al; 169 struct thread *thread; 170 __u32 sz; 171 172 if (!d->ctx_valid || !d_al_p) 173 return -1; 174 175 thread = get_thread(d); 176 if (!thread) 177 return -1; 178 179 addr_location__init(&al); 180 thread__find_symbol_fb(thread, d->sample->cpumode, address, &al); 181 182 al_to_d_al(&al, &d_al); 183 184 d_al.is_kernel_ip = machine__kernel_ip(d->machine, address); 185 186 sz = d_al_p->size; 187 memcpy(d_al_p, &d_al, min((size_t)sz, sizeof(d_al))); 188 d_al_p->size = sz; 189 190 if (has_priv(d_al_p)) 191 d_al_p->priv = memdup(&al, sizeof(al)); 192 else /* Avoid leak for v0 API */ 193 addr_location__exit(&al); 194 195 return 0; 196 } 197 198 static void dlfilter__al_cleanup(void *ctx __maybe_unused, struct perf_dlfilter_al *d_al_p) 199 { 200 struct addr_location *al; 201 202 /* Ensure backward compatibility */ 203 if (!has_priv(d_al_p) || !d_al_p->priv) 204 return; 205 206 al = d_al_p->priv; 207 208 d_al_p->priv = NULL; 209 210 addr_location__exit(al); 211 212 free(al); 213 } 214 215 static const __u8 *dlfilter__insn(void *ctx, __u32 *len) 216 { 217 struct dlfilter *d = (struct dlfilter *)ctx; 218 219 if (!len) 220 return NULL; 221 222 *len = 0; 223 224 if (!d->ctx_valid) 225 return NULL; 226 227 if (d->sample->ip && !d->sample->insn_len) { 228 struct addr_location *al = d->al; 229 230 if (!al->thread && machine__resolve(d->machine, al, d->sample) < 0) 231 return NULL; 232 233 if (thread__maps(al->thread)) { 234 struct machine *machine = maps__machine(thread__maps(al->thread)); 235 236 if (machine) 237 script_fetch_insn(d->sample, al->thread, machine); 238 } 239 } 240 241 if (!d->sample->insn_len) 242 return NULL; 243 244 *len = d->sample->insn_len; 245 246 return (__u8 *)d->sample->insn; 247 } 248 249 static const char *dlfilter__srcline(void *ctx, __u32 *line_no) 250 { 251 struct dlfilter *d = (struct dlfilter *)ctx; 252 struct addr_location *al; 253 unsigned int line = 0; 254 char *srcfile = NULL; 255 struct map *map; 256 struct dso *dso; 257 u64 addr; 258 259 if (!d->ctx_valid || !line_no) 260 return NULL; 261 262 al = get_al(d); 263 if (!al) 264 return NULL; 265 266 map = al->map; 267 addr = al->addr; 268 dso = map ? map__dso(map) : NULL; 269 270 if (dso) 271 srcfile = get_srcline_split(dso, map__rip_2objdump(map, addr), &line); 272 273 *line_no = line; 274 return srcfile; 275 } 276 277 static struct perf_event_attr *dlfilter__attr(void *ctx) 278 { 279 struct dlfilter *d = (struct dlfilter *)ctx; 280 281 if (!d->ctx_valid) 282 return NULL; 283 284 return &d->evsel->core.attr; 285 } 286 287 static __s32 code_read(__u64 ip, struct map *map, struct machine *machine, void *buf, __u32 len) 288 { 289 u64 offset = map__map_ip(map, ip); 290 291 if (ip + len >= map__end(map)) 292 len = map__end(map) - ip; 293 294 return dso__data_read_offset(map__dso(map), machine, offset, buf, len); 295 } 296 297 static __s32 dlfilter__object_code(void *ctx, __u64 ip, void *buf, __u32 len) 298 { 299 struct dlfilter *d = (struct dlfilter *)ctx; 300 struct addr_location *al; 301 struct addr_location a; 302 __s32 ret; 303 304 if (!d->ctx_valid) 305 return -1; 306 307 al = get_al(d); 308 if (!al) 309 return -1; 310 311 if (al->map && ip >= map__start(al->map) && ip < map__end(al->map) && 312 machine__kernel_ip(d->machine, ip) == machine__kernel_ip(d->machine, d->sample->ip)) 313 return code_read(ip, al->map, d->machine, buf, len); 314 315 addr_location__init(&a); 316 317 thread__find_map_fb(al->thread, d->sample->cpumode, ip, &a); 318 ret = a.map ? code_read(ip, a.map, d->machine, buf, len) : -1; 319 320 addr_location__exit(&a); 321 322 return ret; 323 } 324 325 static const struct perf_dlfilter_fns perf_dlfilter_fns = { 326 .resolve_ip = dlfilter__resolve_ip, 327 .resolve_addr = dlfilter__resolve_addr, 328 .args = dlfilter__args, 329 .resolve_address = dlfilter__resolve_address, 330 .al_cleanup = dlfilter__al_cleanup, 331 .insn = dlfilter__insn, 332 .srcline = dlfilter__srcline, 333 .attr = dlfilter__attr, 334 .object_code = dlfilter__object_code, 335 }; 336 337 static char *find_dlfilter(const char *file) 338 { 339 char path[PATH_MAX]; 340 char *exec_path; 341 342 if (strchr(file, '/')) 343 goto out; 344 345 if (!access(file, R_OK)) { 346 /* 347 * Prepend "./" so that dlopen will find the file in the 348 * current directory. 349 */ 350 snprintf(path, sizeof(path), "./%s", file); 351 file = path; 352 goto out; 353 } 354 355 exec_path = get_argv_exec_path(); 356 if (!exec_path) 357 goto out; 358 snprintf(path, sizeof(path), "%s/dlfilters/%s", exec_path, file); 359 free(exec_path); 360 if (!access(path, R_OK)) 361 file = path; 362 out: 363 return strdup(file); 364 } 365 366 #define CHECK_FLAG(x) BUILD_BUG_ON((u64)PERF_DLFILTER_FLAG_ ## x != (u64)PERF_IP_FLAG_ ## x) 367 368 static int dlfilter__init(struct dlfilter *d, const char *file, int dlargc, char **dlargv) 369 { 370 CHECK_FLAG(BRANCH); 371 CHECK_FLAG(CALL); 372 CHECK_FLAG(RETURN); 373 CHECK_FLAG(CONDITIONAL); 374 CHECK_FLAG(SYSCALLRET); 375 CHECK_FLAG(ASYNC); 376 CHECK_FLAG(INTERRUPT); 377 CHECK_FLAG(TX_ABORT); 378 CHECK_FLAG(TRACE_BEGIN); 379 CHECK_FLAG(TRACE_END); 380 CHECK_FLAG(IN_TX); 381 CHECK_FLAG(VMENTRY); 382 CHECK_FLAG(VMEXIT); 383 384 memset(d, 0, sizeof(*d)); 385 d->file = find_dlfilter(file); 386 if (!d->file) 387 return -1; 388 d->dlargc = dlargc; 389 d->dlargv = dlargv; 390 return 0; 391 } 392 393 static void dlfilter__exit(struct dlfilter *d) 394 { 395 zfree(&d->file); 396 } 397 398 static int dlfilter__open(struct dlfilter *d) 399 { 400 d->handle = dlopen(d->file, RTLD_NOW); 401 if (!d->handle) { 402 pr_err("dlopen failed for: '%s'\n", d->file); 403 return -1; 404 } 405 d->start = dlsym(d->handle, "start"); 406 d->filter_event = dlsym(d->handle, "filter_event"); 407 d->filter_event_early = dlsym(d->handle, "filter_event_early"); 408 d->stop = dlsym(d->handle, "stop"); 409 d->fns = dlsym(d->handle, "perf_dlfilter_fns"); 410 if (d->fns) 411 memcpy(d->fns, &perf_dlfilter_fns, sizeof(struct perf_dlfilter_fns)); 412 return 0; 413 } 414 415 static int dlfilter__close(struct dlfilter *d) 416 { 417 return dlclose(d->handle); 418 } 419 420 struct dlfilter *dlfilter__new(const char *file, int dlargc, char **dlargv) 421 { 422 struct dlfilter *d = malloc(sizeof(*d)); 423 424 if (!d) 425 return NULL; 426 427 if (dlfilter__init(d, file, dlargc, dlargv)) 428 goto err_free; 429 430 if (dlfilter__open(d)) 431 goto err_exit; 432 433 return d; 434 435 err_exit: 436 dlfilter__exit(d); 437 err_free: 438 free(d); 439 return NULL; 440 } 441 442 static void dlfilter__free(struct dlfilter *d) 443 { 444 if (d) { 445 dlfilter__exit(d); 446 free(d); 447 } 448 } 449 450 int dlfilter__start(struct dlfilter *d, struct perf_session *session) 451 { 452 if (d) { 453 d->session = session; 454 if (d->start) { 455 int ret; 456 457 d->in_start = true; 458 ret = d->start(&d->data, d); 459 d->in_start = false; 460 return ret; 461 } 462 } 463 return 0; 464 } 465 466 static int dlfilter__stop(struct dlfilter *d) 467 { 468 if (d && d->stop) { 469 int ret; 470 471 d->in_stop = true; 472 ret = d->stop(d->data, d); 473 d->in_stop = false; 474 return ret; 475 } 476 return 0; 477 } 478 479 void dlfilter__cleanup(struct dlfilter *d) 480 { 481 if (d) { 482 dlfilter__stop(d); 483 dlfilter__close(d); 484 dlfilter__free(d); 485 } 486 } 487 488 #define ASSIGN(x) d_sample.x = sample->x 489 490 int dlfilter__do_filter_event(struct dlfilter *d, 491 union perf_event *event, 492 struct perf_sample *sample, 493 struct evsel *evsel, 494 struct machine *machine, 495 struct addr_location *al, 496 struct addr_location *addr_al, 497 bool early) 498 { 499 struct perf_dlfilter_sample d_sample; 500 struct perf_dlfilter_al d_ip_al; 501 struct perf_dlfilter_al d_addr_al; 502 int ret; 503 504 d->event = event; 505 d->sample = sample; 506 d->evsel = evsel; 507 d->machine = machine; 508 d->al = al; 509 d->addr_al = addr_al; 510 d->d_sample = &d_sample; 511 d->d_ip_al = &d_ip_al; 512 d->d_addr_al = &d_addr_al; 513 514 d_sample.size = sizeof(d_sample); 515 d_ip_al.size = 0; /* To indicate d_ip_al is not initialized */ 516 d_addr_al.size = 0; /* To indicate d_addr_al is not initialized */ 517 518 ASSIGN(ip); 519 ASSIGN(pid); 520 ASSIGN(tid); 521 ASSIGN(time); 522 ASSIGN(addr); 523 ASSIGN(id); 524 ASSIGN(stream_id); 525 ASSIGN(period); 526 ASSIGN(weight); 527 ASSIGN(ins_lat); 528 ASSIGN(p_stage_cyc); 529 ASSIGN(transaction); 530 ASSIGN(insn_cnt); 531 ASSIGN(cyc_cnt); 532 ASSIGN(cpu); 533 ASSIGN(flags); 534 ASSIGN(data_src); 535 ASSIGN(phys_addr); 536 ASSIGN(data_page_size); 537 ASSIGN(code_page_size); 538 ASSIGN(cgroup); 539 ASSIGN(cpumode); 540 ASSIGN(misc); 541 ASSIGN(raw_size); 542 ASSIGN(raw_data); 543 ASSIGN(machine_pid); 544 ASSIGN(vcpu); 545 546 if (sample->branch_stack) { 547 d_sample.brstack_nr = sample->branch_stack->nr; 548 d_sample.brstack = (struct perf_branch_entry *)perf_sample__branch_entries(sample); 549 } else { 550 d_sample.brstack_nr = 0; 551 d_sample.brstack = NULL; 552 } 553 554 if (sample->callchain) { 555 d_sample.raw_callchain_nr = sample->callchain->nr; 556 d_sample.raw_callchain = (__u64 *)sample->callchain->ips; 557 } else { 558 d_sample.raw_callchain_nr = 0; 559 d_sample.raw_callchain = NULL; 560 } 561 562 d_sample.addr_correlates_sym = 563 (evsel->core.attr.sample_type & PERF_SAMPLE_ADDR) && 564 sample_addr_correlates_sym(&evsel->core.attr); 565 566 d_sample.event = evsel__name(evsel); 567 568 d->ctx_valid = true; 569 570 if (early) 571 ret = d->filter_event_early(d->data, &d_sample, d); 572 else 573 ret = d->filter_event(d->data, &d_sample, d); 574 575 d->ctx_valid = false; 576 577 return ret; 578 } 579 580 bool get_filter_desc(const char *dirname, const char *name, char **desc, 581 char **long_desc) 582 { 583 char path[PATH_MAX]; 584 void *handle; 585 const char *(*desc_fn)(const char **long_description); 586 587 snprintf(path, sizeof(path), "%s/%s", dirname, name); 588 handle = dlopen(path, RTLD_NOW); 589 if (!handle || !(dlsym(handle, "filter_event") || dlsym(handle, "filter_event_early"))) 590 return false; 591 desc_fn = dlsym(handle, "filter_description"); 592 if (desc_fn) { 593 const char *dsc; 594 const char *long_dsc; 595 596 dsc = desc_fn(&long_dsc); 597 if (dsc) 598 *desc = strdup(dsc); 599 if (long_dsc) 600 *long_desc = strdup(long_dsc); 601 } 602 dlclose(handle); 603 return true; 604 } 605 606 static void list_filters(const char *dirname) 607 { 608 struct dirent *entry; 609 DIR *dir; 610 611 dir = opendir(dirname); 612 if (!dir) 613 return; 614 615 while ((entry = readdir(dir)) != NULL) 616 { 617 size_t n = strlen(entry->d_name); 618 char *long_desc = NULL; 619 char *desc = NULL; 620 621 if (entry->d_type == DT_DIR || n < 4 || 622 strcmp(".so", entry->d_name + n - 3)) 623 continue; 624 if (!get_filter_desc(dirname, entry->d_name, &desc, &long_desc)) 625 continue; 626 printf(" %-36s %s\n", entry->d_name, desc ? desc : ""); 627 if (verbose > 0) { 628 char *p = long_desc; 629 char *line; 630 631 while ((line = strsep(&p, "\n")) != NULL) 632 printf("%39s%s\n", "", line); 633 } 634 free(long_desc); 635 free(desc); 636 } 637 638 closedir(dir); 639 } 640 641 int list_available_dlfilters(const struct option *opt __maybe_unused, 642 const char *s __maybe_unused, 643 int unset __maybe_unused) 644 { 645 char path[PATH_MAX]; 646 char *exec_path; 647 648 printf("List of available dlfilters:\n"); 649 650 list_filters("."); 651 652 exec_path = get_argv_exec_path(); 653 if (!exec_path) 654 goto out; 655 snprintf(path, sizeof(path), "%s/dlfilters", exec_path); 656 657 list_filters(path); 658 659 free(exec_path); 660 out: 661 exit(0); 662 } 663