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(buf: path, PATH_MAX, fmt: "%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(cgroup: 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(r: &cgroup->refcnt, n: 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, str: name); |
149 | |
150 | return cgroup ?: cgroup__new(name, do_open: 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, name: 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(cgroup: 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(r: &cgrp->refcnt)) { |
190 | cgroup__delete(cgroup: cgrp); |
191 | } |
192 | } |
193 | |
194 | struct cgroup *cgroup__get(struct cgroup *cgroup) |
195 | { |
196 | if (cgroup) |
197 | refcount_inc(r: &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(p: cn->name, q: fpath); |
230 | |
231 | list_add_tail(new: &cn->list, head: &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, typeflag: FTW_D, NULL); |
246 | } |
247 | |
248 | static void release_cgroup_list(void) |
249 | { |
250 | struct cgroup_name *cn; |
251 | |
252 | while (!list_empty(head: &cgroup_list)) { |
253 | cn = list_first_entry(&cgroup_list, struct cgroup_name, list); |
254 | list_del(entry: &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(fpath: s); |
279 | free(s); |
280 | if (ret < 0) |
281 | return -1; |
282 | } else { |
283 | if (check_and_add_cgroup_name(fpath: "/" ) < 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(head: &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, str: 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(r: &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(evlist: orig_list, list: &evlist->core.entries); |
441 | evlist->core.nr_entries = 0; |
442 | |
443 | if (metric_events) { |
444 | orig_metric_events = *metric_events; |
445 | rblist__init(rblist: metric_events); |
446 | } else { |
447 | rblist__init(rblist: &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, do_open: 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(orig: pos); |
475 | if (evsel == NULL) |
476 | goto out_err; |
477 | |
478 | cgroup__put(cgrp: evsel->cgrp); |
479 | evsel->cgrp = cgroup__get(cgroup: cgrp); |
480 | |
481 | if (evsel__is_group_leader(evsel: pos)) |
482 | leader = evsel; |
483 | evsel__set_leader(evsel, leader); |
484 | |
485 | evlist__add(evlist: tmp_list, entry: 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(evlist: tmp_list, cgrp, |
493 | new_metric_events: metric_events, |
494 | old_metric_events: &orig_metric_events) < 0) |
495 | goto out_err; |
496 | } |
497 | |
498 | evlist__splice_list_tail(evlist, list: &tmp_list->core.entries); |
499 | tmp_list->core.nr_entries = 0; |
500 | } |
501 | |
502 | if (list_empty(head: &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(evlist: orig_list); |
512 | evlist__delete(evlist: tmp_list); |
513 | rblist__exit(rblist: &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(r: &cgrp->refcnt, n: 1); |
555 | |
556 | rb_link_node(node: &cgrp->node, parent, rb_link: 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(sem: &env->cgroups.lock); |
568 | cgrp = __cgroup__findnew(root: &env->cgroups.tree, id, create: true, path); |
569 | up_write(sem: &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(sem: &env->cgroups.lock); |
583 | cgrp = __cgroup__findnew(root: &env->cgroups.tree, id, create: false, NULL); |
584 | up_read(sem: &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(sem: &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(sem: &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(path: cn->name); |
630 | __cgroup__findnew(root, id: cgrp_id, /*create=*/true, path: name); |
631 | } |
632 | |
633 | release_cgroup_list(); |
634 | } |
635 | |