1 // SPDX-License-Identifier: GPL-2.0 2 #include <subcmd/parse-options.h> 3 #include "evsel.h" 4 #include "cgroup.h" 5 #include "evlist.h" 6 #include "rblist.h" 7 #include "metricgroup.h" 8 #include "stat.h" 9 #include <linux/zalloc.h> 10 #include <sys/types.h> 11 #include <sys/stat.h> 12 #include <sys/statfs.h> 13 #include <fcntl.h> 14 #include <stdlib.h> 15 #include <string.h> 16 #include <api/fs/fs.h> 17 #include <ftw.h> 18 #include <regex.h> 19 20 int nr_cgroups; 21 bool cgrp_event_expanded; 22 23 /* used to match cgroup name with patterns */ 24 struct cgroup_name { 25 struct list_head list; 26 bool used; 27 char name[]; 28 }; 29 static LIST_HEAD(cgroup_list); 30 31 static int open_cgroup(const char *name) 32 { 33 char path[PATH_MAX + 1]; 34 char mnt[PATH_MAX + 1]; 35 int fd; 36 37 38 if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event")) 39 return -1; 40 41 scnprintf(path, PATH_MAX, "%s/%s", mnt, name); 42 43 fd = open(path, O_RDONLY); 44 if (fd == -1) 45 fprintf(stderr, "no access to cgroup %s\n", path); 46 47 return fd; 48 } 49 50 #ifdef HAVE_FILE_HANDLE 51 static u64 __read_cgroup_id(const char *path) 52 { 53 struct { 54 struct file_handle fh; 55 uint64_t cgroup_id; 56 } handle; 57 int mount_id; 58 59 handle.fh.handle_bytes = sizeof(handle.cgroup_id); 60 if (name_to_handle_at(AT_FDCWD, path, &handle.fh, &mount_id, 0) < 0) 61 return -1ULL; 62 63 return handle.cgroup_id; 64 } 65 66 int read_cgroup_id(struct cgroup *cgrp) 67 { 68 char path[PATH_MAX + 1]; 69 char mnt[PATH_MAX + 1]; 70 71 if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, "perf_event")) 72 return -1; 73 74 scnprintf(path, PATH_MAX, "%s/%s", mnt, cgrp->name); 75 76 cgrp->id = __read_cgroup_id(path); 77 return 0; 78 } 79 #else 80 static inline u64 __read_cgroup_id(const char *path __maybe_unused) { return -1ULL; } 81 #endif /* HAVE_FILE_HANDLE */ 82 83 #ifndef CGROUP2_SUPER_MAGIC 84 #define CGROUP2_SUPER_MAGIC 0x63677270 85 #endif 86 87 int cgroup_is_v2(const char *subsys) 88 { 89 char mnt[PATH_MAX + 1]; 90 struct statfs stbuf; 91 92 if (cgroupfs_find_mountpoint(mnt, PATH_MAX + 1, subsys)) 93 return -1; 94 95 if (statfs(mnt, &stbuf) < 0) 96 return -1; 97 98 return (stbuf.f_type == CGROUP2_SUPER_MAGIC); 99 } 100 101 static struct cgroup *evlist__find_cgroup(struct evlist *evlist, const char *str) 102 { 103 struct evsel *counter; 104 /* 105 * check if cgrp is already defined, if so we reuse it 106 */ 107 evlist__for_each_entry(evlist, counter) { 108 if (!counter->cgrp) 109 continue; 110 if (!strcmp(counter->cgrp->name, str)) 111 return cgroup__get(counter->cgrp); 112 } 113 114 return NULL; 115 } 116 117 struct cgroup *cgroup__new(const char *name, bool do_open) 118 { 119 struct cgroup *cgroup = zalloc(sizeof(*cgroup)); 120 121 if (cgroup != NULL) { 122 refcount_set(&cgroup->refcnt, 1); 123 124 cgroup->name = strdup(name); 125 if (!cgroup->name) 126 goto out_err; 127 128 if (do_open) { 129 cgroup->fd = open_cgroup(name); 130 if (cgroup->fd == -1) 131 goto out_free_name; 132 } else { 133 cgroup->fd = -1; 134 } 135 } 136 137 return cgroup; 138 139 out_free_name: 140 zfree(&cgroup->name); 141 out_err: 142 free(cgroup); 143 return NULL; 144 } 145 146 struct cgroup *evlist__findnew_cgroup(struct evlist *evlist, const char *name) 147 { 148 struct cgroup *cgroup = evlist__find_cgroup(evlist, name); 149 150 return cgroup ?: cgroup__new(name, true); 151 } 152 153 static int add_cgroup(struct evlist *evlist, const char *str) 154 { 155 struct evsel *counter; 156 struct cgroup *cgrp = evlist__findnew_cgroup(evlist, str); 157 int n; 158 159 if (!cgrp) 160 return -1; 161 /* 162 * find corresponding event 163 * if add cgroup N, then need to find event N 164 */ 165 n = 0; 166 evlist__for_each_entry(evlist, counter) { 167 if (n == nr_cgroups) 168 goto found; 169 n++; 170 } 171 172 cgroup__put(cgrp); 173 return -1; 174 found: 175 counter->cgrp = cgrp; 176 return 0; 177 } 178 179 static void cgroup__delete(struct cgroup *cgroup) 180 { 181 if (cgroup->fd >= 0) 182 close(cgroup->fd); 183 zfree(&cgroup->name); 184 free(cgroup); 185 } 186 187 void cgroup__put(struct cgroup *cgrp) 188 { 189 if (cgrp && refcount_dec_and_test(&cgrp->refcnt)) { 190 cgroup__delete(cgrp); 191 } 192 } 193 194 struct cgroup *cgroup__get(struct cgroup *cgroup) 195 { 196 if (cgroup) 197 refcount_inc(&cgroup->refcnt); 198 return cgroup; 199 } 200 201 static void evsel__set_default_cgroup(struct evsel *evsel, struct cgroup *cgroup) 202 { 203 if (evsel->cgrp == NULL) 204 evsel->cgrp = cgroup__get(cgroup); 205 } 206 207 void evlist__set_default_cgroup(struct evlist *evlist, struct cgroup *cgroup) 208 { 209 struct evsel *evsel; 210 211 evlist__for_each_entry(evlist, evsel) 212 evsel__set_default_cgroup(evsel, cgroup); 213 } 214 215 /* helper function for ftw() in match_cgroups and list_cgroups */ 216 static int add_cgroup_name(const char *fpath, const struct stat *sb __maybe_unused, 217 int typeflag, struct FTW *ftwbuf __maybe_unused) 218 { 219 struct cgroup_name *cn; 220 221 if (typeflag != FTW_D) 222 return 0; 223 224 cn = malloc(sizeof(*cn) + strlen(fpath) + 1); 225 if (cn == NULL) 226 return -1; 227 228 cn->used = false; 229 strcpy(cn->name, fpath); 230 231 list_add_tail(&cn->list, &cgroup_list); 232 return 0; 233 } 234 235 static int check_and_add_cgroup_name(const char *fpath) 236 { 237 struct cgroup_name *cn; 238 239 list_for_each_entry(cn, &cgroup_list, list) { 240 if (!strcmp(cn->name, fpath)) 241 return 0; 242 } 243 244 /* pretend if it's added by ftw() */ 245 return add_cgroup_name(fpath, NULL, FTW_D, NULL); 246 } 247 248 static void release_cgroup_list(void) 249 { 250 struct cgroup_name *cn; 251 252 while (!list_empty(&cgroup_list)) { 253 cn = list_first_entry(&cgroup_list, struct cgroup_name, list); 254 list_del(&cn->list); 255 free(cn); 256 } 257 } 258 259 /* collect given cgroups only */ 260 static int list_cgroups(const char *str) 261 { 262 const char *p, *e, *eos = str + strlen(str); 263 struct cgroup_name *cn; 264 char *s; 265 266 /* use given name as is when no regex is given */ 267 for (;;) { 268 p = strchr(str, ','); 269 e = p ? p : eos; 270 271 if (e - str) { 272 int ret; 273 274 s = strndup(str, e - str); 275 if (!s) 276 return -1; 277 278 ret = check_and_add_cgroup_name(s); 279 free(s); 280 if (ret < 0) 281 return -1; 282 } else { 283 if (check_and_add_cgroup_name("/") < 0) 284 return -1; 285 } 286 287 if (!p) 288 break; 289 str = p+1; 290 } 291 292 /* these groups will be used */ 293 list_for_each_entry(cn, &cgroup_list, list) 294 cn->used = true; 295 296 return 0; 297 } 298 299 /* collect all cgroups first and then match with the pattern */ 300 static int match_cgroups(const char *str) 301 { 302 char mnt[PATH_MAX]; 303 const char *p, *e, *eos = str + strlen(str); 304 struct cgroup_name *cn; 305 regex_t reg; 306 int prefix_len; 307 char *s; 308 309 if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event")) 310 return -1; 311 312 /* cgroup_name will have a full path, skip the root directory */ 313 prefix_len = strlen(mnt); 314 315 /* collect all cgroups in the cgroup_list */ 316 if (nftw(mnt, add_cgroup_name, 20, 0) < 0) 317 return -1; 318 319 for (;;) { 320 p = strchr(str, ','); 321 e = p ? p : eos; 322 323 /* allow empty cgroups, i.e., skip */ 324 if (e - str) { 325 /* termination added */ 326 s = strndup(str, e - str); 327 if (!s) 328 return -1; 329 if (regcomp(®, s, REG_NOSUB)) { 330 free(s); 331 return -1; 332 } 333 334 /* check cgroup name with the pattern */ 335 list_for_each_entry(cn, &cgroup_list, list) { 336 char *name = cn->name + prefix_len; 337 338 if (name[0] == '/' && name[1]) 339 name++; 340 if (!regexec(®, name, 0, NULL, 0)) 341 cn->used = true; 342 } 343 regfree(®); 344 free(s); 345 } else { 346 /* first entry to root cgroup */ 347 cn = list_first_entry(&cgroup_list, struct cgroup_name, 348 list); 349 cn->used = true; 350 } 351 352 if (!p) 353 break; 354 str = p+1; 355 } 356 return prefix_len; 357 } 358 359 int parse_cgroups(const struct option *opt, const char *str, 360 int unset __maybe_unused) 361 { 362 struct evlist *evlist = *(struct evlist **)opt->value; 363 struct evsel *counter; 364 struct cgroup *cgrp = NULL; 365 const char *p, *e, *eos = str + strlen(str); 366 char *s; 367 int ret, i; 368 369 if (list_empty(&evlist->core.entries)) { 370 fprintf(stderr, "must define events before cgroups\n"); 371 return -1; 372 } 373 374 for (;;) { 375 p = strchr(str, ','); 376 e = p ? p : eos; 377 378 /* allow empty cgroups, i.e., skip */ 379 if (e - str) { 380 /* termination added */ 381 s = strndup(str, e - str); 382 if (!s) 383 return -1; 384 ret = add_cgroup(evlist, s); 385 free(s); 386 if (ret) 387 return -1; 388 } 389 /* nr_cgroups is increased een for empty cgroups */ 390 nr_cgroups++; 391 if (!p) 392 break; 393 str = p+1; 394 } 395 /* for the case one cgroup combine to multiple events */ 396 i = 0; 397 if (nr_cgroups == 1) { 398 evlist__for_each_entry(evlist, counter) { 399 if (i == 0) 400 cgrp = counter->cgrp; 401 else { 402 counter->cgrp = cgrp; 403 refcount_inc(&cgrp->refcnt); 404 } 405 i++; 406 } 407 } 408 return 0; 409 } 410 411 static bool has_pattern_string(const char *str) 412 { 413 return !!strpbrk(str, "{}[]()|*+?^$"); 414 } 415 416 int evlist__expand_cgroup(struct evlist *evlist, const char *str, 417 struct rblist *metric_events, bool open_cgroup) 418 { 419 struct evlist *orig_list, *tmp_list; 420 struct evsel *pos, *evsel, *leader; 421 struct rblist orig_metric_events; 422 struct cgroup *cgrp = NULL; 423 struct cgroup_name *cn; 424 int ret = -1; 425 int prefix_len; 426 427 if (evlist->core.nr_entries == 0) { 428 fprintf(stderr, "must define events before cgroups\n"); 429 return -EINVAL; 430 } 431 432 orig_list = evlist__new(); 433 tmp_list = evlist__new(); 434 if (orig_list == NULL || tmp_list == NULL) { 435 fprintf(stderr, "memory allocation failed\n"); 436 return -ENOMEM; 437 } 438 439 /* save original events and init evlist */ 440 evlist__splice_list_tail(orig_list, &evlist->core.entries); 441 evlist->core.nr_entries = 0; 442 443 if (metric_events) { 444 orig_metric_events = *metric_events; 445 rblist__init(metric_events); 446 } else { 447 rblist__init(&orig_metric_events); 448 } 449 450 if (has_pattern_string(str)) 451 prefix_len = match_cgroups(str); 452 else 453 prefix_len = list_cgroups(str); 454 455 if (prefix_len < 0) 456 goto out_err; 457 458 list_for_each_entry(cn, &cgroup_list, list) { 459 char *name; 460 461 if (!cn->used) 462 continue; 463 464 /* cgroup_name might have a full path, skip the prefix */ 465 name = cn->name + prefix_len; 466 if (name[0] == '/' && name[1]) 467 name++; 468 cgrp = cgroup__new(name, open_cgroup); 469 if (cgrp == NULL) 470 goto out_err; 471 472 leader = NULL; 473 evlist__for_each_entry(orig_list, pos) { 474 evsel = evsel__clone(pos); 475 if (evsel == NULL) 476 goto out_err; 477 478 cgroup__put(evsel->cgrp); 479 evsel->cgrp = cgroup__get(cgrp); 480 481 if (evsel__is_group_leader(pos)) 482 leader = evsel; 483 evsel__set_leader(evsel, leader); 484 485 evlist__add(tmp_list, evsel); 486 } 487 /* cgroup__new() has a refcount, release it here */ 488 cgroup__put(cgrp); 489 nr_cgroups++; 490 491 if (metric_events) { 492 if (metricgroup__copy_metric_events(tmp_list, cgrp, 493 metric_events, 494 &orig_metric_events) < 0) 495 goto out_err; 496 } 497 498 evlist__splice_list_tail(evlist, &tmp_list->core.entries); 499 tmp_list->core.nr_entries = 0; 500 } 501 502 if (list_empty(&evlist->core.entries)) { 503 fprintf(stderr, "no cgroup matched: %s\n", str); 504 goto out_err; 505 } 506 507 ret = 0; 508 cgrp_event_expanded = true; 509 510 out_err: 511 evlist__delete(orig_list); 512 evlist__delete(tmp_list); 513 rblist__exit(&orig_metric_events); 514 release_cgroup_list(); 515 516 return ret; 517 } 518 519 static struct cgroup *__cgroup__findnew(struct rb_root *root, uint64_t id, 520 bool create, const char *path) 521 { 522 struct rb_node **p = &root->rb_node; 523 struct rb_node *parent = NULL; 524 struct cgroup *cgrp; 525 526 while (*p != NULL) { 527 parent = *p; 528 cgrp = rb_entry(parent, struct cgroup, node); 529 530 if (cgrp->id == id) 531 return cgrp; 532 533 if (cgrp->id < id) 534 p = &(*p)->rb_left; 535 else 536 p = &(*p)->rb_right; 537 } 538 539 if (!create) 540 return NULL; 541 542 cgrp = malloc(sizeof(*cgrp)); 543 if (cgrp == NULL) 544 return NULL; 545 546 cgrp->name = strdup(path); 547 if (cgrp->name == NULL) { 548 free(cgrp); 549 return NULL; 550 } 551 552 cgrp->fd = -1; 553 cgrp->id = id; 554 refcount_set(&cgrp->refcnt, 1); 555 556 rb_link_node(&cgrp->node, parent, p); 557 rb_insert_color(&cgrp->node, root); 558 559 return cgrp; 560 } 561 562 struct cgroup *cgroup__findnew(struct perf_env *env, uint64_t id, 563 const char *path) 564 { 565 struct cgroup *cgrp; 566 567 down_write(&env->cgroups.lock); 568 cgrp = __cgroup__findnew(&env->cgroups.tree, id, true, path); 569 up_write(&env->cgroups.lock); 570 return cgrp; 571 } 572 573 struct cgroup *__cgroup__find(struct rb_root *root, uint64_t id) 574 { 575 return __cgroup__findnew(root, id, /*create=*/false, /*path=*/NULL); 576 } 577 578 struct cgroup *cgroup__find(struct perf_env *env, uint64_t id) 579 { 580 struct cgroup *cgrp; 581 582 down_read(&env->cgroups.lock); 583 cgrp = __cgroup__findnew(&env->cgroups.tree, id, false, NULL); 584 up_read(&env->cgroups.lock); 585 return cgrp; 586 } 587 588 void perf_env__purge_cgroups(struct perf_env *env) 589 { 590 struct rb_node *node; 591 struct cgroup *cgrp; 592 593 down_write(&env->cgroups.lock); 594 while (!RB_EMPTY_ROOT(&env->cgroups.tree)) { 595 node = rb_first(&env->cgroups.tree); 596 cgrp = rb_entry(node, struct cgroup, node); 597 598 rb_erase(node, &env->cgroups.tree); 599 cgroup__put(cgrp); 600 } 601 up_write(&env->cgroups.lock); 602 } 603 604 void read_all_cgroups(struct rb_root *root) 605 { 606 char mnt[PATH_MAX]; 607 struct cgroup_name *cn; 608 int prefix_len; 609 610 if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event")) 611 return; 612 613 /* cgroup_name will have a full path, skip the root directory */ 614 prefix_len = strlen(mnt); 615 616 /* collect all cgroups in the cgroup_list */ 617 if (nftw(mnt, add_cgroup_name, 20, 0) < 0) 618 return; 619 620 list_for_each_entry(cn, &cgroup_list, list) { 621 const char *name; 622 u64 cgrp_id; 623 624 /* cgroup_name might have a full path, skip the prefix */ 625 name = cn->name + prefix_len; 626 if (name[0] == '\0') 627 name = "/"; 628 629 cgrp_id = __read_cgroup_id(cn->name); 630 __cgroup__findnew(root, cgrp_id, /*create=*/true, name); 631 } 632 633 release_cgroup_list(); 634 } 635