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