xref: /linux/tools/testing/selftests/cgroup/test_core.c (revision 36ec807b627b4c0a0a382f0ae48eac7187d14b2b)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 #define _GNU_SOURCE
4 #include <linux/limits.h>
5 #include <linux/sched.h>
6 #include <sys/types.h>
7 #include <sys/mman.h>
8 #include <sys/wait.h>
9 #include <unistd.h>
10 #include <fcntl.h>
11 #include <sched.h>
12 #include <stdio.h>
13 #include <errno.h>
14 #include <signal.h>
15 #include <string.h>
16 #include <pthread.h>
17 
18 #include "../kselftest.h"
19 #include "cgroup_util.h"
20 
21 static bool nsdelegate;
22 
23 static int touch_anon(char *buf, size_t size)
24 {
25 	int fd;
26 	char *pos = buf;
27 
28 	fd = open("/dev/urandom", O_RDONLY);
29 	if (fd < 0)
30 		return -1;
31 
32 	while (size > 0) {
33 		ssize_t ret = read(fd, pos, size);
34 
35 		if (ret < 0) {
36 			if (errno != EINTR) {
37 				close(fd);
38 				return -1;
39 			}
40 		} else {
41 			pos += ret;
42 			size -= ret;
43 		}
44 	}
45 	close(fd);
46 
47 	return 0;
48 }
49 
50 static int alloc_and_touch_anon_noexit(const char *cgroup, void *arg)
51 {
52 	int ppid = getppid();
53 	size_t size = (size_t)arg;
54 	void *buf;
55 
56 	buf = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON,
57 		   0, 0);
58 	if (buf == MAP_FAILED)
59 		return -1;
60 
61 	if (touch_anon((char *)buf, size)) {
62 		munmap(buf, size);
63 		return -1;
64 	}
65 
66 	while (getppid() == ppid)
67 		sleep(1);
68 
69 	munmap(buf, size);
70 	return 0;
71 }
72 
73 /*
74  * Create a child process that allocates and touches 100MB, then waits to be
75  * killed. Wait until the child is attached to the cgroup, kill all processes
76  * in that cgroup and wait until "cgroup.procs" is empty. At this point try to
77  * destroy the empty cgroup. The test helps detect race conditions between
78  * dying processes leaving the cgroup and cgroup destruction path.
79  */
80 static int test_cgcore_destroy(const char *root)
81 {
82 	int ret = KSFT_FAIL;
83 	char *cg_test = NULL;
84 	int child_pid;
85 	char buf[PAGE_SIZE];
86 
87 	cg_test = cg_name(root, "cg_test");
88 
89 	if (!cg_test)
90 		goto cleanup;
91 
92 	for (int i = 0; i < 10; i++) {
93 		if (cg_create(cg_test))
94 			goto cleanup;
95 
96 		child_pid = cg_run_nowait(cg_test, alloc_and_touch_anon_noexit,
97 					  (void *) MB(100));
98 
99 		if (child_pid < 0)
100 			goto cleanup;
101 
102 		/* wait for the child to enter cgroup */
103 		if (cg_wait_for_proc_count(cg_test, 1))
104 			goto cleanup;
105 
106 		if (cg_killall(cg_test))
107 			goto cleanup;
108 
109 		/* wait for cgroup to be empty */
110 		while (1) {
111 			if (cg_read(cg_test, "cgroup.procs", buf, sizeof(buf)))
112 				goto cleanup;
113 			if (buf[0] == '\0')
114 				break;
115 			usleep(1000);
116 		}
117 
118 		if (rmdir(cg_test))
119 			goto cleanup;
120 
121 		if (waitpid(child_pid, NULL, 0) < 0)
122 			goto cleanup;
123 	}
124 	ret = KSFT_PASS;
125 cleanup:
126 	if (cg_test)
127 		cg_destroy(cg_test);
128 	free(cg_test);
129 	return ret;
130 }
131 
132 /*
133  * A(0) - B(0) - C(1)
134  *        \ D(0)
135  *
136  * A, B and C's "populated" fields would be 1 while D's 0.
137  * test that after the one process in C is moved to root,
138  * A,B and C's "populated" fields would flip to "0" and file
139  * modified events will be generated on the
140  * "cgroup.events" files of both cgroups.
141  */
142 static int test_cgcore_populated(const char *root)
143 {
144 	int ret = KSFT_FAIL;
145 	int err;
146 	char *cg_test_a = NULL, *cg_test_b = NULL;
147 	char *cg_test_c = NULL, *cg_test_d = NULL;
148 	int cgroup_fd = -EBADF;
149 	pid_t pid;
150 
151 	cg_test_a = cg_name(root, "cg_test_a");
152 	cg_test_b = cg_name(root, "cg_test_a/cg_test_b");
153 	cg_test_c = cg_name(root, "cg_test_a/cg_test_b/cg_test_c");
154 	cg_test_d = cg_name(root, "cg_test_a/cg_test_b/cg_test_d");
155 
156 	if (!cg_test_a || !cg_test_b || !cg_test_c || !cg_test_d)
157 		goto cleanup;
158 
159 	if (cg_create(cg_test_a))
160 		goto cleanup;
161 
162 	if (cg_create(cg_test_b))
163 		goto cleanup;
164 
165 	if (cg_create(cg_test_c))
166 		goto cleanup;
167 
168 	if (cg_create(cg_test_d))
169 		goto cleanup;
170 
171 	if (cg_enter_current(cg_test_c))
172 		goto cleanup;
173 
174 	if (cg_read_strcmp(cg_test_a, "cgroup.events", "populated 1\n"))
175 		goto cleanup;
176 
177 	if (cg_read_strcmp(cg_test_b, "cgroup.events", "populated 1\n"))
178 		goto cleanup;
179 
180 	if (cg_read_strcmp(cg_test_c, "cgroup.events", "populated 1\n"))
181 		goto cleanup;
182 
183 	if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n"))
184 		goto cleanup;
185 
186 	if (cg_enter_current(root))
187 		goto cleanup;
188 
189 	if (cg_read_strcmp(cg_test_a, "cgroup.events", "populated 0\n"))
190 		goto cleanup;
191 
192 	if (cg_read_strcmp(cg_test_b, "cgroup.events", "populated 0\n"))
193 		goto cleanup;
194 
195 	if (cg_read_strcmp(cg_test_c, "cgroup.events", "populated 0\n"))
196 		goto cleanup;
197 
198 	if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n"))
199 		goto cleanup;
200 
201 	/* Test that we can directly clone into a new cgroup. */
202 	cgroup_fd = dirfd_open_opath(cg_test_d);
203 	if (cgroup_fd < 0)
204 		goto cleanup;
205 
206 	pid = clone_into_cgroup(cgroup_fd);
207 	if (pid < 0) {
208 		if (errno == ENOSYS)
209 			goto cleanup_pass;
210 		goto cleanup;
211 	}
212 
213 	if (pid == 0) {
214 		if (raise(SIGSTOP))
215 			exit(EXIT_FAILURE);
216 		exit(EXIT_SUCCESS);
217 	}
218 
219 	err = cg_read_strcmp(cg_test_d, "cgroup.events", "populated 1\n");
220 
221 	(void)clone_reap(pid, WSTOPPED);
222 	(void)kill(pid, SIGCONT);
223 	(void)clone_reap(pid, WEXITED);
224 
225 	if (err)
226 		goto cleanup;
227 
228 	if (cg_read_strcmp(cg_test_d, "cgroup.events", "populated 0\n"))
229 		goto cleanup;
230 
231 	/* Remove cgroup. */
232 	if (cg_test_d) {
233 		cg_destroy(cg_test_d);
234 		free(cg_test_d);
235 		cg_test_d = NULL;
236 	}
237 
238 	pid = clone_into_cgroup(cgroup_fd);
239 	if (pid < 0)
240 		goto cleanup_pass;
241 	if (pid == 0)
242 		exit(EXIT_SUCCESS);
243 	(void)clone_reap(pid, WEXITED);
244 	goto cleanup;
245 
246 cleanup_pass:
247 	ret = KSFT_PASS;
248 
249 cleanup:
250 	if (cg_test_d)
251 		cg_destroy(cg_test_d);
252 	if (cg_test_c)
253 		cg_destroy(cg_test_c);
254 	if (cg_test_b)
255 		cg_destroy(cg_test_b);
256 	if (cg_test_a)
257 		cg_destroy(cg_test_a);
258 	free(cg_test_d);
259 	free(cg_test_c);
260 	free(cg_test_b);
261 	free(cg_test_a);
262 	if (cgroup_fd >= 0)
263 		close(cgroup_fd);
264 	return ret;
265 }
266 
267 /*
268  * A (domain threaded) - B (threaded) - C (domain)
269  *
270  * test that C can't be used until it is turned into a
271  * threaded cgroup.  "cgroup.type" file will report "domain (invalid)" in
272  * these cases. Operations which fail due to invalid topology use
273  * EOPNOTSUPP as the errno.
274  */
275 static int test_cgcore_invalid_domain(const char *root)
276 {
277 	int ret = KSFT_FAIL;
278 	char *grandparent = NULL, *parent = NULL, *child = NULL;
279 
280 	grandparent = cg_name(root, "cg_test_grandparent");
281 	parent = cg_name(root, "cg_test_grandparent/cg_test_parent");
282 	child = cg_name(root, "cg_test_grandparent/cg_test_parent/cg_test_child");
283 	if (!parent || !child || !grandparent)
284 		goto cleanup;
285 
286 	if (cg_create(grandparent))
287 		goto cleanup;
288 
289 	if (cg_create(parent))
290 		goto cleanup;
291 
292 	if (cg_create(child))
293 		goto cleanup;
294 
295 	if (cg_write(parent, "cgroup.type", "threaded"))
296 		goto cleanup;
297 
298 	if (cg_read_strcmp(child, "cgroup.type", "domain invalid\n"))
299 		goto cleanup;
300 
301 	if (!cg_enter_current(child))
302 		goto cleanup;
303 
304 	if (errno != EOPNOTSUPP)
305 		goto cleanup;
306 
307 	if (!clone_into_cgroup_run_wait(child))
308 		goto cleanup;
309 
310 	if (errno == ENOSYS)
311 		goto cleanup_pass;
312 
313 	if (errno != EOPNOTSUPP)
314 		goto cleanup;
315 
316 cleanup_pass:
317 	ret = KSFT_PASS;
318 
319 cleanup:
320 	cg_enter_current(root);
321 	if (child)
322 		cg_destroy(child);
323 	if (parent)
324 		cg_destroy(parent);
325 	if (grandparent)
326 		cg_destroy(grandparent);
327 	free(child);
328 	free(parent);
329 	free(grandparent);
330 	return ret;
331 }
332 
333 /*
334  * Test that when a child becomes threaded
335  * the parent type becomes domain threaded.
336  */
337 static int test_cgcore_parent_becomes_threaded(const char *root)
338 {
339 	int ret = KSFT_FAIL;
340 	char *parent = NULL, *child = NULL;
341 
342 	parent = cg_name(root, "cg_test_parent");
343 	child = cg_name(root, "cg_test_parent/cg_test_child");
344 	if (!parent || !child)
345 		goto cleanup;
346 
347 	if (cg_create(parent))
348 		goto cleanup;
349 
350 	if (cg_create(child))
351 		goto cleanup;
352 
353 	if (cg_write(child, "cgroup.type", "threaded"))
354 		goto cleanup;
355 
356 	if (cg_read_strcmp(parent, "cgroup.type", "domain threaded\n"))
357 		goto cleanup;
358 
359 	ret = KSFT_PASS;
360 
361 cleanup:
362 	if (child)
363 		cg_destroy(child);
364 	if (parent)
365 		cg_destroy(parent);
366 	free(child);
367 	free(parent);
368 	return ret;
369 
370 }
371 
372 /*
373  * Test that there's no internal process constrain on threaded cgroups.
374  * You can add threads/processes on a parent with a controller enabled.
375  */
376 static int test_cgcore_no_internal_process_constraint_on_threads(const char *root)
377 {
378 	int ret = KSFT_FAIL;
379 	char *parent = NULL, *child = NULL;
380 
381 	if (cg_read_strstr(root, "cgroup.controllers", "cpu") ||
382 	    cg_write(root, "cgroup.subtree_control", "+cpu")) {
383 		ret = KSFT_SKIP;
384 		goto cleanup;
385 	}
386 
387 	parent = cg_name(root, "cg_test_parent");
388 	child = cg_name(root, "cg_test_parent/cg_test_child");
389 	if (!parent || !child)
390 		goto cleanup;
391 
392 	if (cg_create(parent))
393 		goto cleanup;
394 
395 	if (cg_create(child))
396 		goto cleanup;
397 
398 	if (cg_write(parent, "cgroup.type", "threaded"))
399 		goto cleanup;
400 
401 	if (cg_write(child, "cgroup.type", "threaded"))
402 		goto cleanup;
403 
404 	if (cg_write(parent, "cgroup.subtree_control", "+cpu"))
405 		goto cleanup;
406 
407 	if (cg_enter_current(parent))
408 		goto cleanup;
409 
410 	ret = KSFT_PASS;
411 
412 cleanup:
413 	cg_enter_current(root);
414 	cg_enter_current(root);
415 	if (child)
416 		cg_destroy(child);
417 	if (parent)
418 		cg_destroy(parent);
419 	free(child);
420 	free(parent);
421 	return ret;
422 }
423 
424 /*
425  * Test that you can't enable a controller on a child if it's not enabled
426  * on the parent.
427  */
428 static int test_cgcore_top_down_constraint_enable(const char *root)
429 {
430 	int ret = KSFT_FAIL;
431 	char *parent = NULL, *child = NULL;
432 
433 	parent = cg_name(root, "cg_test_parent");
434 	child = cg_name(root, "cg_test_parent/cg_test_child");
435 	if (!parent || !child)
436 		goto cleanup;
437 
438 	if (cg_create(parent))
439 		goto cleanup;
440 
441 	if (cg_create(child))
442 		goto cleanup;
443 
444 	if (!cg_write(child, "cgroup.subtree_control", "+memory"))
445 		goto cleanup;
446 
447 	ret = KSFT_PASS;
448 
449 cleanup:
450 	if (child)
451 		cg_destroy(child);
452 	if (parent)
453 		cg_destroy(parent);
454 	free(child);
455 	free(parent);
456 	return ret;
457 }
458 
459 /*
460  * Test that you can't disable a controller on a parent
461  * if it's enabled in a child.
462  */
463 static int test_cgcore_top_down_constraint_disable(const char *root)
464 {
465 	int ret = KSFT_FAIL;
466 	char *parent = NULL, *child = NULL;
467 
468 	parent = cg_name(root, "cg_test_parent");
469 	child = cg_name(root, "cg_test_parent/cg_test_child");
470 	if (!parent || !child)
471 		goto cleanup;
472 
473 	if (cg_create(parent))
474 		goto cleanup;
475 
476 	if (cg_create(child))
477 		goto cleanup;
478 
479 	if (cg_write(parent, "cgroup.subtree_control", "+memory"))
480 		goto cleanup;
481 
482 	if (cg_write(child, "cgroup.subtree_control", "+memory"))
483 		goto cleanup;
484 
485 	if (!cg_write(parent, "cgroup.subtree_control", "-memory"))
486 		goto cleanup;
487 
488 	ret = KSFT_PASS;
489 
490 cleanup:
491 	if (child)
492 		cg_destroy(child);
493 	if (parent)
494 		cg_destroy(parent);
495 	free(child);
496 	free(parent);
497 	return ret;
498 }
499 
500 /*
501  * Test internal process constraint.
502  * You can't add a pid to a domain parent if a controller is enabled.
503  */
504 static int test_cgcore_internal_process_constraint(const char *root)
505 {
506 	int ret = KSFT_FAIL;
507 	char *parent = NULL, *child = NULL;
508 
509 	parent = cg_name(root, "cg_test_parent");
510 	child = cg_name(root, "cg_test_parent/cg_test_child");
511 	if (!parent || !child)
512 		goto cleanup;
513 
514 	if (cg_create(parent))
515 		goto cleanup;
516 
517 	if (cg_create(child))
518 		goto cleanup;
519 
520 	if (cg_write(parent, "cgroup.subtree_control", "+memory"))
521 		goto cleanup;
522 
523 	if (!cg_enter_current(parent))
524 		goto cleanup;
525 
526 	if (!clone_into_cgroup_run_wait(parent))
527 		goto cleanup;
528 
529 	ret = KSFT_PASS;
530 
531 cleanup:
532 	if (child)
533 		cg_destroy(child);
534 	if (parent)
535 		cg_destroy(parent);
536 	free(child);
537 	free(parent);
538 	return ret;
539 }
540 
541 static void *dummy_thread_fn(void *arg)
542 {
543 	return (void *)(size_t)pause();
544 }
545 
546 /*
547  * Test threadgroup migration.
548  * All threads of a process are migrated together.
549  */
550 static int test_cgcore_proc_migration(const char *root)
551 {
552 	int ret = KSFT_FAIL;
553 	int t, c_threads = 0, n_threads = 13;
554 	char *src = NULL, *dst = NULL;
555 	pthread_t threads[n_threads];
556 
557 	src = cg_name(root, "cg_src");
558 	dst = cg_name(root, "cg_dst");
559 	if (!src || !dst)
560 		goto cleanup;
561 
562 	if (cg_create(src))
563 		goto cleanup;
564 	if (cg_create(dst))
565 		goto cleanup;
566 
567 	if (cg_enter_current(src))
568 		goto cleanup;
569 
570 	for (c_threads = 0; c_threads < n_threads; ++c_threads) {
571 		if (pthread_create(&threads[c_threads], NULL, dummy_thread_fn, NULL))
572 			goto cleanup;
573 	}
574 
575 	cg_enter_current(dst);
576 	if (cg_read_lc(dst, "cgroup.threads") != n_threads + 1)
577 		goto cleanup;
578 
579 	ret = KSFT_PASS;
580 
581 cleanup:
582 	for (t = 0; t < c_threads; ++t) {
583 		pthread_cancel(threads[t]);
584 	}
585 
586 	for (t = 0; t < c_threads; ++t) {
587 		pthread_join(threads[t], NULL);
588 	}
589 
590 	cg_enter_current(root);
591 
592 	if (dst)
593 		cg_destroy(dst);
594 	if (src)
595 		cg_destroy(src);
596 	free(dst);
597 	free(src);
598 	return ret;
599 }
600 
601 static void *migrating_thread_fn(void *arg)
602 {
603 	int g, i, n_iterations = 1000;
604 	char **grps = arg;
605 	char lines[3][PATH_MAX];
606 
607 	for (g = 1; g < 3; ++g)
608 		snprintf(lines[g], sizeof(lines[g]), "0::%s", grps[g] + strlen(grps[0]));
609 
610 	for (i = 0; i < n_iterations; ++i) {
611 		cg_enter_current_thread(grps[(i % 2) + 1]);
612 
613 		if (proc_read_strstr(0, 1, "cgroup", lines[(i % 2) + 1]))
614 			return (void *)-1;
615 	}
616 	return NULL;
617 }
618 
619 /*
620  * Test single thread migration.
621  * Threaded cgroups allow successful migration of a thread.
622  */
623 static int test_cgcore_thread_migration(const char *root)
624 {
625 	int ret = KSFT_FAIL;
626 	char *dom = NULL;
627 	char line[PATH_MAX];
628 	char *grps[3] = { (char *)root, NULL, NULL };
629 	pthread_t thr;
630 	void *retval;
631 
632 	dom = cg_name(root, "cg_dom");
633 	grps[1] = cg_name(root, "cg_dom/cg_src");
634 	grps[2] = cg_name(root, "cg_dom/cg_dst");
635 	if (!grps[1] || !grps[2] || !dom)
636 		goto cleanup;
637 
638 	if (cg_create(dom))
639 		goto cleanup;
640 	if (cg_create(grps[1]))
641 		goto cleanup;
642 	if (cg_create(grps[2]))
643 		goto cleanup;
644 
645 	if (cg_write(grps[1], "cgroup.type", "threaded"))
646 		goto cleanup;
647 	if (cg_write(grps[2], "cgroup.type", "threaded"))
648 		goto cleanup;
649 
650 	if (cg_enter_current(grps[1]))
651 		goto cleanup;
652 
653 	if (pthread_create(&thr, NULL, migrating_thread_fn, grps))
654 		goto cleanup;
655 
656 	if (pthread_join(thr, &retval))
657 		goto cleanup;
658 
659 	if (retval)
660 		goto cleanup;
661 
662 	snprintf(line, sizeof(line), "0::%s", grps[1] + strlen(grps[0]));
663 	if (proc_read_strstr(0, 1, "cgroup", line))
664 		goto cleanup;
665 
666 	ret = KSFT_PASS;
667 
668 cleanup:
669 	cg_enter_current(root);
670 	if (grps[2])
671 		cg_destroy(grps[2]);
672 	if (grps[1])
673 		cg_destroy(grps[1]);
674 	if (dom)
675 		cg_destroy(dom);
676 	free(grps[2]);
677 	free(grps[1]);
678 	free(dom);
679 	return ret;
680 }
681 
682 /*
683  * cgroup migration permission check should be performed based on the
684  * credentials at the time of open instead of write.
685  */
686 static int test_cgcore_lesser_euid_open(const char *root)
687 {
688 	const uid_t test_euid = TEST_UID;
689 	int ret = KSFT_FAIL;
690 	char *cg_test_a = NULL, *cg_test_b = NULL;
691 	char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL;
692 	int cg_test_b_procs_fd = -1;
693 	uid_t saved_uid;
694 
695 	cg_test_a = cg_name(root, "cg_test_a");
696 	cg_test_b = cg_name(root, "cg_test_b");
697 
698 	if (!cg_test_a || !cg_test_b)
699 		goto cleanup;
700 
701 	cg_test_a_procs = cg_name(cg_test_a, "cgroup.procs");
702 	cg_test_b_procs = cg_name(cg_test_b, "cgroup.procs");
703 
704 	if (!cg_test_a_procs || !cg_test_b_procs)
705 		goto cleanup;
706 
707 	if (cg_create(cg_test_a) || cg_create(cg_test_b))
708 		goto cleanup;
709 
710 	if (cg_enter_current(cg_test_a))
711 		goto cleanup;
712 
713 	if (chown(cg_test_a_procs, test_euid, -1) ||
714 	    chown(cg_test_b_procs, test_euid, -1))
715 		goto cleanup;
716 
717 	saved_uid = geteuid();
718 	if (seteuid(test_euid))
719 		goto cleanup;
720 
721 	cg_test_b_procs_fd = open(cg_test_b_procs, O_RDWR);
722 
723 	if (seteuid(saved_uid))
724 		goto cleanup;
725 
726 	if (cg_test_b_procs_fd < 0)
727 		goto cleanup;
728 
729 	if (write(cg_test_b_procs_fd, "0", 1) >= 0 || errno != EACCES)
730 		goto cleanup;
731 
732 	ret = KSFT_PASS;
733 
734 cleanup:
735 	cg_enter_current(root);
736 	if (cg_test_b_procs_fd >= 0)
737 		close(cg_test_b_procs_fd);
738 	if (cg_test_b)
739 		cg_destroy(cg_test_b);
740 	if (cg_test_a)
741 		cg_destroy(cg_test_a);
742 	free(cg_test_b_procs);
743 	free(cg_test_a_procs);
744 	free(cg_test_b);
745 	free(cg_test_a);
746 	return ret;
747 }
748 
749 struct lesser_ns_open_thread_arg {
750 	const char	*path;
751 	int		fd;
752 	int		err;
753 };
754 
755 static int lesser_ns_open_thread_fn(void *arg)
756 {
757 	struct lesser_ns_open_thread_arg *targ = arg;
758 
759 	targ->fd = open(targ->path, O_RDWR);
760 	targ->err = errno;
761 	return 0;
762 }
763 
764 /*
765  * cgroup migration permission check should be performed based on the cgroup
766  * namespace at the time of open instead of write.
767  */
768 static int test_cgcore_lesser_ns_open(const char *root)
769 {
770 	static char stack[65536];
771 	const uid_t test_euid = 65534;	/* usually nobody, any !root is fine */
772 	int ret = KSFT_FAIL;
773 	char *cg_test_a = NULL, *cg_test_b = NULL;
774 	char *cg_test_a_procs = NULL, *cg_test_b_procs = NULL;
775 	int cg_test_b_procs_fd = -1;
776 	struct lesser_ns_open_thread_arg targ = { .fd = -1 };
777 	pid_t pid;
778 	int status;
779 
780 	if (!nsdelegate)
781 		return KSFT_SKIP;
782 
783 	cg_test_a = cg_name(root, "cg_test_a");
784 	cg_test_b = cg_name(root, "cg_test_b");
785 
786 	if (!cg_test_a || !cg_test_b)
787 		goto cleanup;
788 
789 	cg_test_a_procs = cg_name(cg_test_a, "cgroup.procs");
790 	cg_test_b_procs = cg_name(cg_test_b, "cgroup.procs");
791 
792 	if (!cg_test_a_procs || !cg_test_b_procs)
793 		goto cleanup;
794 
795 	if (cg_create(cg_test_a) || cg_create(cg_test_b))
796 		goto cleanup;
797 
798 	if (cg_enter_current(cg_test_b))
799 		goto cleanup;
800 
801 	if (chown(cg_test_a_procs, test_euid, -1) ||
802 	    chown(cg_test_b_procs, test_euid, -1))
803 		goto cleanup;
804 
805 	targ.path = cg_test_b_procs;
806 	pid = clone(lesser_ns_open_thread_fn, stack + sizeof(stack),
807 		    CLONE_NEWCGROUP | CLONE_FILES | CLONE_VM | SIGCHLD,
808 		    &targ);
809 	if (pid < 0)
810 		goto cleanup;
811 
812 	if (waitpid(pid, &status, 0) < 0)
813 		goto cleanup;
814 
815 	if (!WIFEXITED(status))
816 		goto cleanup;
817 
818 	cg_test_b_procs_fd = targ.fd;
819 	if (cg_test_b_procs_fd < 0)
820 		goto cleanup;
821 
822 	if (cg_enter_current(cg_test_a))
823 		goto cleanup;
824 
825 	if ((status = write(cg_test_b_procs_fd, "0", 1)) >= 0 || errno != ENOENT)
826 		goto cleanup;
827 
828 	ret = KSFT_PASS;
829 
830 cleanup:
831 	cg_enter_current(root);
832 	if (cg_test_b_procs_fd >= 0)
833 		close(cg_test_b_procs_fd);
834 	if (cg_test_b)
835 		cg_destroy(cg_test_b);
836 	if (cg_test_a)
837 		cg_destroy(cg_test_a);
838 	free(cg_test_b_procs);
839 	free(cg_test_a_procs);
840 	free(cg_test_b);
841 	free(cg_test_a);
842 	return ret;
843 }
844 
845 #define T(x) { x, #x }
846 struct corecg_test {
847 	int (*fn)(const char *root);
848 	const char *name;
849 } tests[] = {
850 	T(test_cgcore_internal_process_constraint),
851 	T(test_cgcore_top_down_constraint_enable),
852 	T(test_cgcore_top_down_constraint_disable),
853 	T(test_cgcore_no_internal_process_constraint_on_threads),
854 	T(test_cgcore_parent_becomes_threaded),
855 	T(test_cgcore_invalid_domain),
856 	T(test_cgcore_populated),
857 	T(test_cgcore_proc_migration),
858 	T(test_cgcore_thread_migration),
859 	T(test_cgcore_destroy),
860 	T(test_cgcore_lesser_euid_open),
861 	T(test_cgcore_lesser_ns_open),
862 };
863 #undef T
864 
865 int main(int argc, char *argv[])
866 {
867 	char root[PATH_MAX];
868 	int i, ret = EXIT_SUCCESS;
869 
870 	if (cg_find_unified_root(root, sizeof(root), &nsdelegate))
871 		ksft_exit_skip("cgroup v2 isn't mounted\n");
872 
873 	if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
874 		if (cg_write(root, "cgroup.subtree_control", "+memory"))
875 			ksft_exit_skip("Failed to set memory controller\n");
876 
877 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
878 		switch (tests[i].fn(root)) {
879 		case KSFT_PASS:
880 			ksft_test_result_pass("%s\n", tests[i].name);
881 			break;
882 		case KSFT_SKIP:
883 			ksft_test_result_skip("%s\n", tests[i].name);
884 			break;
885 		default:
886 			ret = EXIT_FAILURE;
887 			ksft_test_result_fail("%s\n", tests[i].name);
888 			break;
889 		}
890 	}
891 
892 	return ret;
893 }
894