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
469 /* the cgroup can go away in the meantime */
470 cgrp = cgroup__new(name, open_cgroup);
471 if (cgrp == NULL)
472 continue;
473
474 leader = NULL;
475 evlist__for_each_entry(orig_list, pos) {
476 evsel = evsel__clone(pos);
477 if (evsel == NULL)
478 goto out_err;
479
480 cgroup__put(evsel->cgrp);
481 evsel->cgrp = cgroup__get(cgrp);
482
483 if (evsel__is_group_leader(pos))
484 leader = evsel;
485 evsel__set_leader(evsel, leader);
486
487 evlist__add(tmp_list, evsel);
488 }
489 /* cgroup__new() has a refcount, release it here */
490 cgroup__put(cgrp);
491 nr_cgroups++;
492
493 if (metric_events) {
494 if (metricgroup__copy_metric_events(tmp_list, cgrp,
495 metric_events,
496 &orig_metric_events) < 0)
497 goto out_err;
498 }
499
500 evlist__splice_list_tail(evlist, &tmp_list->core.entries);
501 tmp_list->core.nr_entries = 0;
502 }
503
504 if (list_empty(&evlist->core.entries)) {
505 fprintf(stderr, "no cgroup matched: %s\n", str);
506 goto out_err;
507 }
508
509 ret = 0;
510 cgrp_event_expanded = true;
511
512 out_err:
513 evlist__delete(orig_list);
514 evlist__delete(tmp_list);
515 rblist__exit(&orig_metric_events);
516 release_cgroup_list();
517
518 return ret;
519 }
520
521 static struct cgroup *__cgroup__findnew(struct rb_root *root, uint64_t id,
522 bool create, const char *path)
523 {
524 struct rb_node **p = &root->rb_node;
525 struct rb_node *parent = NULL;
526 struct cgroup *cgrp;
527
528 while (*p != NULL) {
529 parent = *p;
530 cgrp = rb_entry(parent, struct cgroup, node);
531
532 if (cgrp->id == id)
533 return cgrp;
534
535 if (cgrp->id < id)
536 p = &(*p)->rb_left;
537 else
538 p = &(*p)->rb_right;
539 }
540
541 if (!create)
542 return NULL;
543
544 cgrp = malloc(sizeof(*cgrp));
545 if (cgrp == NULL)
546 return NULL;
547
548 cgrp->name = strdup(path);
549 if (cgrp->name == NULL) {
550 free(cgrp);
551 return NULL;
552 }
553
554 cgrp->fd = -1;
555 cgrp->id = id;
556 refcount_set(&cgrp->refcnt, 1);
557
558 rb_link_node(&cgrp->node, parent, p);
559 rb_insert_color(&cgrp->node, root);
560
561 return cgrp;
562 }
563
564 struct cgroup *cgroup__findnew(struct perf_env *env, uint64_t id,
565 const char *path)
566 {
567 struct cgroup *cgrp;
568
569 down_write(&env->cgroups.lock);
570 cgrp = __cgroup__findnew(&env->cgroups.tree, id, true, path);
571 up_write(&env->cgroups.lock);
572 return cgrp;
573 }
574
575 struct cgroup *__cgroup__find(struct rb_root *root, uint64_t id)
576 {
577 return __cgroup__findnew(root, id, /*create=*/false, /*path=*/NULL);
578 }
579
580 struct cgroup *cgroup__find(struct perf_env *env, uint64_t id)
581 {
582 struct cgroup *cgrp;
583
584 down_read(&env->cgroups.lock);
585 cgrp = __cgroup__findnew(&env->cgroups.tree, id, false, NULL);
586 up_read(&env->cgroups.lock);
587 return cgrp;
588 }
589
590 void perf_env__purge_cgroups(struct perf_env *env)
591 {
592 struct rb_node *node;
593 struct cgroup *cgrp;
594
595 down_write(&env->cgroups.lock);
596 while (!RB_EMPTY_ROOT(&env->cgroups.tree)) {
597 node = rb_first(&env->cgroups.tree);
598 cgrp = rb_entry(node, struct cgroup, node);
599
600 rb_erase(node, &env->cgroups.tree);
601 cgroup__put(cgrp);
602 }
603 up_write(&env->cgroups.lock);
604 }
605
606 void read_all_cgroups(struct rb_root *root)
607 {
608 char mnt[PATH_MAX];
609 struct cgroup_name *cn;
610 int prefix_len;
611
612 if (cgroupfs_find_mountpoint(mnt, sizeof(mnt), "perf_event"))
613 return;
614
615 /* cgroup_name will have a full path, skip the root directory */
616 prefix_len = strlen(mnt);
617
618 /* collect all cgroups in the cgroup_list */
619 if (nftw(mnt, add_cgroup_name, 20, 0) < 0)
620 return;
621
622 list_for_each_entry(cn, &cgroup_list, list) {
623 const char *name;
624 u64 cgrp_id;
625
626 /* cgroup_name might have a full path, skip the prefix */
627 name = cn->name + prefix_len;
628 if (name[0] == '\0')
629 name = "/";
630
631 cgrp_id = __read_cgroup_id(cn->name);
632 __cgroup__findnew(root, cgrp_id, /*create=*/true, name);
633 }
634
635 release_cgroup_list();
636 }
637
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