1 /* SPDX-License-Identifier: GPL-2.0 */
2 #define _GNU_SOURCE
3 
4 #include <linux/limits.h>
5 #include <linux/oom.h>
6 #include <fcntl.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <sys/stat.h>
11 #include <sys/types.h>
12 #include <unistd.h>
13 #include <sys/socket.h>
14 #include <sys/wait.h>
15 #include <arpa/inet.h>
16 #include <netinet/in.h>
17 #include <netdb.h>
18 #include <errno.h>
19 #include <sys/mman.h>
20 
21 #include "../kselftest.h"
22 #include "cgroup_util.h"
23 
24 static bool has_localevents;
25 static bool has_recursiveprot;
26 
27 /*
28  * This test creates two nested cgroups with and without enabling
29  * the memory controller.
30  */
31 static int test_memcg_subtree_control(const char *root)
32 {
33 	char *parent, *child, *parent2 = NULL, *child2 = NULL;
34 	int ret = KSFT_FAIL;
35 	char buf[PAGE_SIZE];
36 
37 	/* Create two nested cgroups with the memory controller enabled */
38 	parent = cg_name(root, "memcg_test_0");
39 	child = cg_name(root, "memcg_test_0/memcg_test_1");
40 	if (!parent || !child)
41 		goto cleanup_free;
42 
43 	if (cg_create(parent))
44 		goto cleanup_free;
45 
46 	if (cg_write(parent, "cgroup.subtree_control", "+memory"))
47 		goto cleanup_parent;
48 
49 	if (cg_create(child))
50 		goto cleanup_parent;
51 
52 	if (cg_read_strstr(child, "cgroup.controllers", "memory"))
53 		goto cleanup_child;
54 
55 	/* Create two nested cgroups without enabling memory controller */
56 	parent2 = cg_name(root, "memcg_test_1");
57 	child2 = cg_name(root, "memcg_test_1/memcg_test_1");
58 	if (!parent2 || !child2)
59 		goto cleanup_free2;
60 
61 	if (cg_create(parent2))
62 		goto cleanup_free2;
63 
64 	if (cg_create(child2))
65 		goto cleanup_parent2;
66 
67 	if (cg_read(child2, "cgroup.controllers", buf, sizeof(buf)))
68 		goto cleanup_all;
69 
70 	if (!cg_read_strstr(child2, "cgroup.controllers", "memory"))
71 		goto cleanup_all;
72 
73 	ret = KSFT_PASS;
74 
75 cleanup_all:
76 	cg_destroy(child2);
77 cleanup_parent2:
78 	cg_destroy(parent2);
79 cleanup_free2:
80 	free(parent2);
81 	free(child2);
82 cleanup_child:
83 	cg_destroy(child);
84 cleanup_parent:
85 	cg_destroy(parent);
86 cleanup_free:
87 	free(parent);
88 	free(child);
89 
90 	return ret;
91 }
92 
93 static int alloc_anon_50M_check(const char *cgroup, void *arg)
94 {
95 	size_t size = MB(50);
96 	char *buf, *ptr;
97 	long anon, current;
98 	int ret = -1;
99 
100 	buf = malloc(size);
101 	if (buf == NULL) {
102 		fprintf(stderr, "malloc() failed\n");
103 		return -1;
104 	}
105 
106 	for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE)
107 		*ptr = 0;
108 
109 	current = cg_read_long(cgroup, "memory.current");
110 	if (current < size)
111 		goto cleanup;
112 
113 	if (!values_close(size, current, 3))
114 		goto cleanup;
115 
116 	anon = cg_read_key_long(cgroup, "memory.stat", "anon ");
117 	if (anon < 0)
118 		goto cleanup;
119 
120 	if (!values_close(anon, current, 3))
121 		goto cleanup;
122 
123 	ret = 0;
124 cleanup:
125 	free(buf);
126 	return ret;
127 }
128 
129 static int alloc_pagecache_50M_check(const char *cgroup, void *arg)
130 {
131 	size_t size = MB(50);
132 	int ret = -1;
133 	long current, file;
134 	int fd;
135 
136 	fd = get_temp_fd();
137 	if (fd < 0)
138 		return -1;
139 
140 	if (alloc_pagecache(fd, size))
141 		goto cleanup;
142 
143 	current = cg_read_long(cgroup, "memory.current");
144 	if (current < size)
145 		goto cleanup;
146 
147 	file = cg_read_key_long(cgroup, "memory.stat", "file ");
148 	if (file < 0)
149 		goto cleanup;
150 
151 	if (!values_close(file, current, 10))
152 		goto cleanup;
153 
154 	ret = 0;
155 
156 cleanup:
157 	close(fd);
158 	return ret;
159 }
160 
161 /*
162  * This test create a memory cgroup, allocates
163  * some anonymous memory and some pagecache
164  * and check memory.current and some memory.stat values.
165  */
166 static int test_memcg_current(const char *root)
167 {
168 	int ret = KSFT_FAIL;
169 	long current;
170 	char *memcg;
171 
172 	memcg = cg_name(root, "memcg_test");
173 	if (!memcg)
174 		goto cleanup;
175 
176 	if (cg_create(memcg))
177 		goto cleanup;
178 
179 	current = cg_read_long(memcg, "memory.current");
180 	if (current != 0)
181 		goto cleanup;
182 
183 	if (cg_run(memcg, alloc_anon_50M_check, NULL))
184 		goto cleanup;
185 
186 	if (cg_run(memcg, alloc_pagecache_50M_check, NULL))
187 		goto cleanup;
188 
189 	ret = KSFT_PASS;
190 
191 cleanup:
192 	cg_destroy(memcg);
193 	free(memcg);
194 
195 	return ret;
196 }
197 
198 static int alloc_pagecache_50M_noexit(const char *cgroup, void *arg)
199 {
200 	int fd = (long)arg;
201 	int ppid = getppid();
202 
203 	if (alloc_pagecache(fd, MB(50)))
204 		return -1;
205 
206 	while (getppid() == ppid)
207 		sleep(1);
208 
209 	return 0;
210 }
211 
212 static int alloc_anon_noexit(const char *cgroup, void *arg)
213 {
214 	int ppid = getppid();
215 	size_t size = (unsigned long)arg;
216 	char *buf, *ptr;
217 
218 	buf = malloc(size);
219 	if (buf == NULL) {
220 		fprintf(stderr, "malloc() failed\n");
221 		return -1;
222 	}
223 
224 	for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE)
225 		*ptr = 0;
226 
227 	while (getppid() == ppid)
228 		sleep(1);
229 
230 	free(buf);
231 	return 0;
232 }
233 
234 /*
235  * Wait until processes are killed asynchronously by the OOM killer
236  * If we exceed a timeout, fail.
237  */
238 static int cg_test_proc_killed(const char *cgroup)
239 {
240 	int limit;
241 
242 	for (limit = 10; limit > 0; limit--) {
243 		if (cg_read_strcmp(cgroup, "cgroup.procs", "") == 0)
244 			return 0;
245 
246 		usleep(100000);
247 	}
248 	return -1;
249 }
250 
251 static bool reclaim_until(const char *memcg, long goal);
252 
253 /*
254  * First, this test creates the following hierarchy:
255  * A       memory.min = 0,    memory.max = 200M
256  * A/B     memory.min = 50M
257  * A/B/C   memory.min = 75M,  memory.current = 50M
258  * A/B/D   memory.min = 25M,  memory.current = 50M
259  * A/B/E   memory.min = 0,    memory.current = 50M
260  * A/B/F   memory.min = 500M, memory.current = 0
261  *
262  * (or memory.low if we test soft protection)
263  *
264  * Usages are pagecache and the test keeps a running
265  * process in every leaf cgroup.
266  * Then it creates A/G and creates a significant
267  * memory pressure in A.
268  *
269  * Then it checks actual memory usages and expects that:
270  * A/B    memory.current ~= 50M
271  * A/B/C  memory.current ~= 29M
272  * A/B/D  memory.current ~= 21M
273  * A/B/E  memory.current ~= 0
274  * A/B/F  memory.current  = 0
275  * (for origin of the numbers, see model in memcg_protection.m.)
276  *
277  * After that it tries to allocate more than there is
278  * unprotected memory in A available, and checks that:
279  * a) memory.min protects pagecache even in this case,
280  * b) memory.low allows reclaiming page cache with low events.
281  *
282  * Then we try to reclaim from A/B/C using memory.reclaim until its
283  * usage reaches 10M.
284  * This makes sure that:
285  * (a) We ignore the protection of the reclaim target memcg.
286  * (b) The previously calculated emin value (~29M) should be dismissed.
287  */
288 static int test_memcg_protection(const char *root, bool min)
289 {
290 	int ret = KSFT_FAIL, rc;
291 	char *parent[3] = {NULL};
292 	char *children[4] = {NULL};
293 	const char *attribute = min ? "memory.min" : "memory.low";
294 	long c[4];
295 	long current;
296 	int i, attempts;
297 	int fd;
298 
299 	fd = get_temp_fd();
300 	if (fd < 0)
301 		goto cleanup;
302 
303 	parent[0] = cg_name(root, "memcg_test_0");
304 	if (!parent[0])
305 		goto cleanup;
306 
307 	parent[1] = cg_name(parent[0], "memcg_test_1");
308 	if (!parent[1])
309 		goto cleanup;
310 
311 	parent[2] = cg_name(parent[0], "memcg_test_2");
312 	if (!parent[2])
313 		goto cleanup;
314 
315 	if (cg_create(parent[0]))
316 		goto cleanup;
317 
318 	if (cg_read_long(parent[0], attribute)) {
319 		/* No memory.min on older kernels is fine */
320 		if (min)
321 			ret = KSFT_SKIP;
322 		goto cleanup;
323 	}
324 
325 	if (cg_write(parent[0], "cgroup.subtree_control", "+memory"))
326 		goto cleanup;
327 
328 	if (cg_write(parent[0], "memory.max", "200M"))
329 		goto cleanup;
330 
331 	if (cg_write(parent[0], "memory.swap.max", "0"))
332 		goto cleanup;
333 
334 	if (cg_create(parent[1]))
335 		goto cleanup;
336 
337 	if (cg_write(parent[1], "cgroup.subtree_control", "+memory"))
338 		goto cleanup;
339 
340 	if (cg_create(parent[2]))
341 		goto cleanup;
342 
343 	for (i = 0; i < ARRAY_SIZE(children); i++) {
344 		children[i] = cg_name_indexed(parent[1], "child_memcg", i);
345 		if (!children[i])
346 			goto cleanup;
347 
348 		if (cg_create(children[i]))
349 			goto cleanup;
350 
351 		if (i > 2)
352 			continue;
353 
354 		cg_run_nowait(children[i], alloc_pagecache_50M_noexit,
355 			      (void *)(long)fd);
356 	}
357 
358 	if (cg_write(parent[1],   attribute, "50M"))
359 		goto cleanup;
360 	if (cg_write(children[0], attribute, "75M"))
361 		goto cleanup;
362 	if (cg_write(children[1], attribute, "25M"))
363 		goto cleanup;
364 	if (cg_write(children[2], attribute, "0"))
365 		goto cleanup;
366 	if (cg_write(children[3], attribute, "500M"))
367 		goto cleanup;
368 
369 	attempts = 0;
370 	while (!values_close(cg_read_long(parent[1], "memory.current"),
371 			     MB(150), 3)) {
372 		if (attempts++ > 5)
373 			break;
374 		sleep(1);
375 	}
376 
377 	if (cg_run(parent[2], alloc_anon, (void *)MB(148)))
378 		goto cleanup;
379 
380 	if (!values_close(cg_read_long(parent[1], "memory.current"), MB(50), 3))
381 		goto cleanup;
382 
383 	for (i = 0; i < ARRAY_SIZE(children); i++)
384 		c[i] = cg_read_long(children[i], "memory.current");
385 
386 	if (!values_close(c[0], MB(29), 10))
387 		goto cleanup;
388 
389 	if (!values_close(c[1], MB(21), 10))
390 		goto cleanup;
391 
392 	if (c[3] != 0)
393 		goto cleanup;
394 
395 	rc = cg_run(parent[2], alloc_anon, (void *)MB(170));
396 	if (min && !rc)
397 		goto cleanup;
398 	else if (!min && rc) {
399 		fprintf(stderr,
400 			"memory.low prevents from allocating anon memory\n");
401 		goto cleanup;
402 	}
403 
404 	current = min ? MB(50) : MB(30);
405 	if (!values_close(cg_read_long(parent[1], "memory.current"), current, 3))
406 		goto cleanup;
407 
408 	if (!reclaim_until(children[0], MB(10)))
409 		goto cleanup;
410 
411 	if (min) {
412 		ret = KSFT_PASS;
413 		goto cleanup;
414 	}
415 
416 	for (i = 0; i < ARRAY_SIZE(children); i++) {
417 		int no_low_events_index = 1;
418 		long low, oom;
419 
420 		oom = cg_read_key_long(children[i], "memory.events", "oom ");
421 		low = cg_read_key_long(children[i], "memory.events", "low ");
422 
423 		if (oom)
424 			goto cleanup;
425 		if (i <= no_low_events_index && low <= 0)
426 			goto cleanup;
427 		if (i > no_low_events_index && low)
428 			goto cleanup;
429 
430 	}
431 
432 	ret = KSFT_PASS;
433 
434 cleanup:
435 	for (i = ARRAY_SIZE(children) - 1; i >= 0; i--) {
436 		if (!children[i])
437 			continue;
438 
439 		cg_destroy(children[i]);
440 		free(children[i]);
441 	}
442 
443 	for (i = ARRAY_SIZE(parent) - 1; i >= 0; i--) {
444 		if (!parent[i])
445 			continue;
446 
447 		cg_destroy(parent[i]);
448 		free(parent[i]);
449 	}
450 	close(fd);
451 	return ret;
452 }
453 
454 static int test_memcg_min(const char *root)
455 {
456 	return test_memcg_protection(root, true);
457 }
458 
459 static int test_memcg_low(const char *root)
460 {
461 	return test_memcg_protection(root, false);
462 }
463 
464 static int alloc_pagecache_max_30M(const char *cgroup, void *arg)
465 {
466 	size_t size = MB(50);
467 	int ret = -1;
468 	long current, high, max;
469 	int fd;
470 
471 	high = cg_read_long(cgroup, "memory.high");
472 	max = cg_read_long(cgroup, "memory.max");
473 	if (high != MB(30) && max != MB(30))
474 		return -1;
475 
476 	fd = get_temp_fd();
477 	if (fd < 0)
478 		return -1;
479 
480 	if (alloc_pagecache(fd, size))
481 		goto cleanup;
482 
483 	current = cg_read_long(cgroup, "memory.current");
484 	if (!values_close(current, MB(30), 5))
485 		goto cleanup;
486 
487 	ret = 0;
488 
489 cleanup:
490 	close(fd);
491 	return ret;
492 
493 }
494 
495 /*
496  * This test checks that memory.high limits the amount of
497  * memory which can be consumed by either anonymous memory
498  * or pagecache.
499  */
500 static int test_memcg_high(const char *root)
501 {
502 	int ret = KSFT_FAIL;
503 	char *memcg;
504 	long high;
505 
506 	memcg = cg_name(root, "memcg_test");
507 	if (!memcg)
508 		goto cleanup;
509 
510 	if (cg_create(memcg))
511 		goto cleanup;
512 
513 	if (cg_read_strcmp(memcg, "memory.high", "max\n"))
514 		goto cleanup;
515 
516 	if (cg_write(memcg, "memory.swap.max", "0"))
517 		goto cleanup;
518 
519 	if (cg_write(memcg, "memory.high", "30M"))
520 		goto cleanup;
521 
522 	if (cg_run(memcg, alloc_anon, (void *)MB(31)))
523 		goto cleanup;
524 
525 	if (!cg_run(memcg, alloc_pagecache_50M_check, NULL))
526 		goto cleanup;
527 
528 	if (cg_run(memcg, alloc_pagecache_max_30M, NULL))
529 		goto cleanup;
530 
531 	high = cg_read_key_long(memcg, "memory.events", "high ");
532 	if (high <= 0)
533 		goto cleanup;
534 
535 	ret = KSFT_PASS;
536 
537 cleanup:
538 	cg_destroy(memcg);
539 	free(memcg);
540 
541 	return ret;
542 }
543 
544 static int alloc_anon_mlock(const char *cgroup, void *arg)
545 {
546 	size_t size = (size_t)arg;
547 	void *buf;
548 
549 	buf = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON,
550 		   0, 0);
551 	if (buf == MAP_FAILED)
552 		return -1;
553 
554 	mlock(buf, size);
555 	munmap(buf, size);
556 	return 0;
557 }
558 
559 /*
560  * This test checks that memory.high is able to throttle big single shot
561  * allocation i.e. large allocation within one kernel entry.
562  */
563 static int test_memcg_high_sync(const char *root)
564 {
565 	int ret = KSFT_FAIL, pid, fd = -1;
566 	char *memcg;
567 	long pre_high, pre_max;
568 	long post_high, post_max;
569 
570 	memcg = cg_name(root, "memcg_test");
571 	if (!memcg)
572 		goto cleanup;
573 
574 	if (cg_create(memcg))
575 		goto cleanup;
576 
577 	pre_high = cg_read_key_long(memcg, "memory.events", "high ");
578 	pre_max = cg_read_key_long(memcg, "memory.events", "max ");
579 	if (pre_high < 0 || pre_max < 0)
580 		goto cleanup;
581 
582 	if (cg_write(memcg, "memory.swap.max", "0"))
583 		goto cleanup;
584 
585 	if (cg_write(memcg, "memory.high", "30M"))
586 		goto cleanup;
587 
588 	if (cg_write(memcg, "memory.max", "140M"))
589 		goto cleanup;
590 
591 	fd = memcg_prepare_for_wait(memcg);
592 	if (fd < 0)
593 		goto cleanup;
594 
595 	pid = cg_run_nowait(memcg, alloc_anon_mlock, (void *)MB(200));
596 	if (pid < 0)
597 		goto cleanup;
598 
599 	cg_wait_for(fd);
600 
601 	post_high = cg_read_key_long(memcg, "memory.events", "high ");
602 	post_max = cg_read_key_long(memcg, "memory.events", "max ");
603 	if (post_high < 0 || post_max < 0)
604 		goto cleanup;
605 
606 	if (pre_high == post_high || pre_max != post_max)
607 		goto cleanup;
608 
609 	ret = KSFT_PASS;
610 
611 cleanup:
612 	if (fd >= 0)
613 		close(fd);
614 	cg_destroy(memcg);
615 	free(memcg);
616 
617 	return ret;
618 }
619 
620 /*
621  * This test checks that memory.max limits the amount of
622  * memory which can be consumed by either anonymous memory
623  * or pagecache.
624  */
625 static int test_memcg_max(const char *root)
626 {
627 	int ret = KSFT_FAIL;
628 	char *memcg;
629 	long current, max;
630 
631 	memcg = cg_name(root, "memcg_test");
632 	if (!memcg)
633 		goto cleanup;
634 
635 	if (cg_create(memcg))
636 		goto cleanup;
637 
638 	if (cg_read_strcmp(memcg, "memory.max", "max\n"))
639 		goto cleanup;
640 
641 	if (cg_write(memcg, "memory.swap.max", "0"))
642 		goto cleanup;
643 
644 	if (cg_write(memcg, "memory.max", "30M"))
645 		goto cleanup;
646 
647 	/* Should be killed by OOM killer */
648 	if (!cg_run(memcg, alloc_anon, (void *)MB(100)))
649 		goto cleanup;
650 
651 	if (cg_run(memcg, alloc_pagecache_max_30M, NULL))
652 		goto cleanup;
653 
654 	current = cg_read_long(memcg, "memory.current");
655 	if (current > MB(30) || !current)
656 		goto cleanup;
657 
658 	max = cg_read_key_long(memcg, "memory.events", "max ");
659 	if (max <= 0)
660 		goto cleanup;
661 
662 	ret = KSFT_PASS;
663 
664 cleanup:
665 	cg_destroy(memcg);
666 	free(memcg);
667 
668 	return ret;
669 }
670 
671 /*
672  * Reclaim from @memcg until usage reaches @goal by writing to
673  * memory.reclaim.
674  *
675  * This function will return false if the usage is already below the
676  * goal.
677  *
678  * This function assumes that writing to memory.reclaim is the only
679  * source of change in memory.current (no concurrent allocations or
680  * reclaim).
681  *
682  * This function makes sure memory.reclaim is sane. It will return
683  * false if memory.reclaim's error codes do not make sense, even if
684  * the usage goal was satisfied.
685  */
686 static bool reclaim_until(const char *memcg, long goal)
687 {
688 	char buf[64];
689 	int retries, err;
690 	long current, to_reclaim;
691 	bool reclaimed = false;
692 
693 	for (retries = 5; retries > 0; retries--) {
694 		current = cg_read_long(memcg, "memory.current");
695 
696 		if (current < goal || values_close(current, goal, 3))
697 			break;
698 		/* Did memory.reclaim return 0 incorrectly? */
699 		else if (reclaimed)
700 			return false;
701 
702 		to_reclaim = current - goal;
703 		snprintf(buf, sizeof(buf), "%ld", to_reclaim);
704 		err = cg_write(memcg, "memory.reclaim", buf);
705 		if (!err)
706 			reclaimed = true;
707 		else if (err != -EAGAIN)
708 			return false;
709 	}
710 	return reclaimed;
711 }
712 
713 /*
714  * This test checks that memory.reclaim reclaims the given
715  * amount of memory (from both anon and file, if possible).
716  */
717 static int test_memcg_reclaim(const char *root)
718 {
719 	int ret = KSFT_FAIL, fd, retries;
720 	char *memcg;
721 	long current, expected_usage;
722 
723 	memcg = cg_name(root, "memcg_test");
724 	if (!memcg)
725 		goto cleanup;
726 
727 	if (cg_create(memcg))
728 		goto cleanup;
729 
730 	current = cg_read_long(memcg, "memory.current");
731 	if (current != 0)
732 		goto cleanup;
733 
734 	fd = get_temp_fd();
735 	if (fd < 0)
736 		goto cleanup;
737 
738 	cg_run_nowait(memcg, alloc_pagecache_50M_noexit, (void *)(long)fd);
739 
740 	/*
741 	 * If swap is enabled, try to reclaim from both anon and file, else try
742 	 * to reclaim from file only.
743 	 */
744 	if (is_swap_enabled()) {
745 		cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(50));
746 		expected_usage = MB(100);
747 	} else
748 		expected_usage = MB(50);
749 
750 	/*
751 	 * Wait until current usage reaches the expected usage (or we run out of
752 	 * retries).
753 	 */
754 	retries = 5;
755 	while (!values_close(cg_read_long(memcg, "memory.current"),
756 			    expected_usage, 10)) {
757 		if (retries--) {
758 			sleep(1);
759 			continue;
760 		} else {
761 			fprintf(stderr,
762 				"failed to allocate %ld for memcg reclaim test\n",
763 				expected_usage);
764 			goto cleanup;
765 		}
766 	}
767 
768 	/*
769 	 * Reclaim until current reaches 30M, this makes sure we hit both anon
770 	 * and file if swap is enabled.
771 	 */
772 	if (!reclaim_until(memcg, MB(30)))
773 		goto cleanup;
774 
775 	ret = KSFT_PASS;
776 cleanup:
777 	cg_destroy(memcg);
778 	free(memcg);
779 	close(fd);
780 
781 	return ret;
782 }
783 
784 static int alloc_anon_50M_check_swap(const char *cgroup, void *arg)
785 {
786 	long mem_max = (long)arg;
787 	size_t size = MB(50);
788 	char *buf, *ptr;
789 	long mem_current, swap_current;
790 	int ret = -1;
791 
792 	buf = malloc(size);
793 	if (buf == NULL) {
794 		fprintf(stderr, "malloc() failed\n");
795 		return -1;
796 	}
797 
798 	for (ptr = buf; ptr < buf + size; ptr += PAGE_SIZE)
799 		*ptr = 0;
800 
801 	mem_current = cg_read_long(cgroup, "memory.current");
802 	if (!mem_current || !values_close(mem_current, mem_max, 3))
803 		goto cleanup;
804 
805 	swap_current = cg_read_long(cgroup, "memory.swap.current");
806 	if (!swap_current ||
807 	    !values_close(mem_current + swap_current, size, 3))
808 		goto cleanup;
809 
810 	ret = 0;
811 cleanup:
812 	free(buf);
813 	return ret;
814 }
815 
816 /*
817  * This test checks that memory.swap.max limits the amount of
818  * anonymous memory which can be swapped out.
819  */
820 static int test_memcg_swap_max(const char *root)
821 {
822 	int ret = KSFT_FAIL;
823 	char *memcg;
824 	long max;
825 
826 	if (!is_swap_enabled())
827 		return KSFT_SKIP;
828 
829 	memcg = cg_name(root, "memcg_test");
830 	if (!memcg)
831 		goto cleanup;
832 
833 	if (cg_create(memcg))
834 		goto cleanup;
835 
836 	if (cg_read_long(memcg, "memory.swap.current")) {
837 		ret = KSFT_SKIP;
838 		goto cleanup;
839 	}
840 
841 	if (cg_read_strcmp(memcg, "memory.max", "max\n"))
842 		goto cleanup;
843 
844 	if (cg_read_strcmp(memcg, "memory.swap.max", "max\n"))
845 		goto cleanup;
846 
847 	if (cg_write(memcg, "memory.swap.max", "30M"))
848 		goto cleanup;
849 
850 	if (cg_write(memcg, "memory.max", "30M"))
851 		goto cleanup;
852 
853 	/* Should be killed by OOM killer */
854 	if (!cg_run(memcg, alloc_anon, (void *)MB(100)))
855 		goto cleanup;
856 
857 	if (cg_read_key_long(memcg, "memory.events", "oom ") != 1)
858 		goto cleanup;
859 
860 	if (cg_read_key_long(memcg, "memory.events", "oom_kill ") != 1)
861 		goto cleanup;
862 
863 	if (cg_run(memcg, alloc_anon_50M_check_swap, (void *)MB(30)))
864 		goto cleanup;
865 
866 	max = cg_read_key_long(memcg, "memory.events", "max ");
867 	if (max <= 0)
868 		goto cleanup;
869 
870 	ret = KSFT_PASS;
871 
872 cleanup:
873 	cg_destroy(memcg);
874 	free(memcg);
875 
876 	return ret;
877 }
878 
879 /*
880  * This test disables swapping and tries to allocate anonymous memory
881  * up to OOM. Then it checks for oom and oom_kill events in
882  * memory.events.
883  */
884 static int test_memcg_oom_events(const char *root)
885 {
886 	int ret = KSFT_FAIL;
887 	char *memcg;
888 
889 	memcg = cg_name(root, "memcg_test");
890 	if (!memcg)
891 		goto cleanup;
892 
893 	if (cg_create(memcg))
894 		goto cleanup;
895 
896 	if (cg_write(memcg, "memory.max", "30M"))
897 		goto cleanup;
898 
899 	if (cg_write(memcg, "memory.swap.max", "0"))
900 		goto cleanup;
901 
902 	if (!cg_run(memcg, alloc_anon, (void *)MB(100)))
903 		goto cleanup;
904 
905 	if (cg_read_strcmp(memcg, "cgroup.procs", ""))
906 		goto cleanup;
907 
908 	if (cg_read_key_long(memcg, "memory.events", "oom ") != 1)
909 		goto cleanup;
910 
911 	if (cg_read_key_long(memcg, "memory.events", "oom_kill ") != 1)
912 		goto cleanup;
913 
914 	ret = KSFT_PASS;
915 
916 cleanup:
917 	cg_destroy(memcg);
918 	free(memcg);
919 
920 	return ret;
921 }
922 
923 struct tcp_server_args {
924 	unsigned short port;
925 	int ctl[2];
926 };
927 
928 static int tcp_server(const char *cgroup, void *arg)
929 {
930 	struct tcp_server_args *srv_args = arg;
931 	struct sockaddr_in6 saddr = { 0 };
932 	socklen_t slen = sizeof(saddr);
933 	int sk, client_sk, ctl_fd, yes = 1, ret = -1;
934 
935 	close(srv_args->ctl[0]);
936 	ctl_fd = srv_args->ctl[1];
937 
938 	saddr.sin6_family = AF_INET6;
939 	saddr.sin6_addr = in6addr_any;
940 	saddr.sin6_port = htons(srv_args->port);
941 
942 	sk = socket(AF_INET6, SOCK_STREAM, 0);
943 	if (sk < 0)
944 		return ret;
945 
946 	if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes)) < 0)
947 		goto cleanup;
948 
949 	if (bind(sk, (struct sockaddr *)&saddr, slen)) {
950 		write(ctl_fd, &errno, sizeof(errno));
951 		goto cleanup;
952 	}
953 
954 	if (listen(sk, 1))
955 		goto cleanup;
956 
957 	ret = 0;
958 	if (write(ctl_fd, &ret, sizeof(ret)) != sizeof(ret)) {
959 		ret = -1;
960 		goto cleanup;
961 	}
962 
963 	client_sk = accept(sk, NULL, NULL);
964 	if (client_sk < 0)
965 		goto cleanup;
966 
967 	ret = -1;
968 	for (;;) {
969 		uint8_t buf[0x100000];
970 
971 		if (write(client_sk, buf, sizeof(buf)) <= 0) {
972 			if (errno == ECONNRESET)
973 				ret = 0;
974 			break;
975 		}
976 	}
977 
978 	close(client_sk);
979 
980 cleanup:
981 	close(sk);
982 	return ret;
983 }
984 
985 static int tcp_client(const char *cgroup, unsigned short port)
986 {
987 	const char server[] = "localhost";
988 	struct addrinfo *ai;
989 	char servport[6];
990 	int retries = 0x10; /* nice round number */
991 	int sk, ret;
992 	long allocated;
993 
994 	allocated = cg_read_long(cgroup, "memory.current");
995 	snprintf(servport, sizeof(servport), "%hd", port);
996 	ret = getaddrinfo(server, servport, NULL, &ai);
997 	if (ret)
998 		return ret;
999 
1000 	sk = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
1001 	if (sk < 0)
1002 		goto free_ainfo;
1003 
1004 	ret = connect(sk, ai->ai_addr, ai->ai_addrlen);
1005 	if (ret < 0)
1006 		goto close_sk;
1007 
1008 	ret = KSFT_FAIL;
1009 	while (retries--) {
1010 		uint8_t buf[0x100000];
1011 		long current, sock;
1012 
1013 		if (read(sk, buf, sizeof(buf)) <= 0)
1014 			goto close_sk;
1015 
1016 		current = cg_read_long(cgroup, "memory.current");
1017 		sock = cg_read_key_long(cgroup, "memory.stat", "sock ");
1018 
1019 		if (current < 0 || sock < 0)
1020 			goto close_sk;
1021 
1022 		/* exclude the memory not related to socket connection */
1023 		if (values_close(current - allocated, sock, 10)) {
1024 			ret = KSFT_PASS;
1025 			break;
1026 		}
1027 	}
1028 
1029 close_sk:
1030 	close(sk);
1031 free_ainfo:
1032 	freeaddrinfo(ai);
1033 	return ret;
1034 }
1035 
1036 /*
1037  * This test checks socket memory accounting.
1038  * The test forks a TCP server listens on a random port between 1000
1039  * and 61000. Once it gets a client connection, it starts writing to
1040  * its socket.
1041  * The TCP client interleaves reads from the socket with check whether
1042  * memory.current and memory.stat.sock are similar.
1043  */
1044 static int test_memcg_sock(const char *root)
1045 {
1046 	int bind_retries = 5, ret = KSFT_FAIL, pid, err;
1047 	unsigned short port;
1048 	char *memcg;
1049 
1050 	memcg = cg_name(root, "memcg_test");
1051 	if (!memcg)
1052 		goto cleanup;
1053 
1054 	if (cg_create(memcg))
1055 		goto cleanup;
1056 
1057 	while (bind_retries--) {
1058 		struct tcp_server_args args;
1059 
1060 		if (pipe(args.ctl))
1061 			goto cleanup;
1062 
1063 		port = args.port = 1000 + rand() % 60000;
1064 
1065 		pid = cg_run_nowait(memcg, tcp_server, &args);
1066 		if (pid < 0)
1067 			goto cleanup;
1068 
1069 		close(args.ctl[1]);
1070 		if (read(args.ctl[0], &err, sizeof(err)) != sizeof(err))
1071 			goto cleanup;
1072 		close(args.ctl[0]);
1073 
1074 		if (!err)
1075 			break;
1076 		if (err != EADDRINUSE)
1077 			goto cleanup;
1078 
1079 		waitpid(pid, NULL, 0);
1080 	}
1081 
1082 	if (err == EADDRINUSE) {
1083 		ret = KSFT_SKIP;
1084 		goto cleanup;
1085 	}
1086 
1087 	if (tcp_client(memcg, port) != KSFT_PASS)
1088 		goto cleanup;
1089 
1090 	waitpid(pid, &err, 0);
1091 	if (WEXITSTATUS(err))
1092 		goto cleanup;
1093 
1094 	if (cg_read_long(memcg, "memory.current") < 0)
1095 		goto cleanup;
1096 
1097 	if (cg_read_key_long(memcg, "memory.stat", "sock "))
1098 		goto cleanup;
1099 
1100 	ret = KSFT_PASS;
1101 
1102 cleanup:
1103 	cg_destroy(memcg);
1104 	free(memcg);
1105 
1106 	return ret;
1107 }
1108 
1109 /*
1110  * This test disables swapping and tries to allocate anonymous memory
1111  * up to OOM with memory.group.oom set. Then it checks that all
1112  * processes in the leaf were killed. It also checks that oom_events
1113  * were propagated to the parent level.
1114  */
1115 static int test_memcg_oom_group_leaf_events(const char *root)
1116 {
1117 	int ret = KSFT_FAIL;
1118 	char *parent, *child;
1119 	long parent_oom_events;
1120 
1121 	parent = cg_name(root, "memcg_test_0");
1122 	child = cg_name(root, "memcg_test_0/memcg_test_1");
1123 
1124 	if (!parent || !child)
1125 		goto cleanup;
1126 
1127 	if (cg_create(parent))
1128 		goto cleanup;
1129 
1130 	if (cg_create(child))
1131 		goto cleanup;
1132 
1133 	if (cg_write(parent, "cgroup.subtree_control", "+memory"))
1134 		goto cleanup;
1135 
1136 	if (cg_write(child, "memory.max", "50M"))
1137 		goto cleanup;
1138 
1139 	if (cg_write(child, "memory.swap.max", "0"))
1140 		goto cleanup;
1141 
1142 	if (cg_write(child, "memory.oom.group", "1"))
1143 		goto cleanup;
1144 
1145 	cg_run_nowait(parent, alloc_anon_noexit, (void *) MB(60));
1146 	cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
1147 	cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
1148 	if (!cg_run(child, alloc_anon, (void *)MB(100)))
1149 		goto cleanup;
1150 
1151 	if (cg_test_proc_killed(child))
1152 		goto cleanup;
1153 
1154 	if (cg_read_key_long(child, "memory.events", "oom_kill ") <= 0)
1155 		goto cleanup;
1156 
1157 	parent_oom_events = cg_read_key_long(
1158 			parent, "memory.events", "oom_kill ");
1159 	/*
1160 	 * If memory_localevents is not enabled (the default), the parent should
1161 	 * count OOM events in its children groups. Otherwise, it should not
1162 	 * have observed any events.
1163 	 */
1164 	if (has_localevents && parent_oom_events != 0)
1165 		goto cleanup;
1166 	else if (!has_localevents && parent_oom_events <= 0)
1167 		goto cleanup;
1168 
1169 	ret = KSFT_PASS;
1170 
1171 cleanup:
1172 	if (child)
1173 		cg_destroy(child);
1174 	if (parent)
1175 		cg_destroy(parent);
1176 	free(child);
1177 	free(parent);
1178 
1179 	return ret;
1180 }
1181 
1182 /*
1183  * This test disables swapping and tries to allocate anonymous memory
1184  * up to OOM with memory.group.oom set. Then it checks that all
1185  * processes in the parent and leaf were killed.
1186  */
1187 static int test_memcg_oom_group_parent_events(const char *root)
1188 {
1189 	int ret = KSFT_FAIL;
1190 	char *parent, *child;
1191 
1192 	parent = cg_name(root, "memcg_test_0");
1193 	child = cg_name(root, "memcg_test_0/memcg_test_1");
1194 
1195 	if (!parent || !child)
1196 		goto cleanup;
1197 
1198 	if (cg_create(parent))
1199 		goto cleanup;
1200 
1201 	if (cg_create(child))
1202 		goto cleanup;
1203 
1204 	if (cg_write(parent, "memory.max", "80M"))
1205 		goto cleanup;
1206 
1207 	if (cg_write(parent, "memory.swap.max", "0"))
1208 		goto cleanup;
1209 
1210 	if (cg_write(parent, "memory.oom.group", "1"))
1211 		goto cleanup;
1212 
1213 	cg_run_nowait(parent, alloc_anon_noexit, (void *) MB(60));
1214 	cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
1215 	cg_run_nowait(child, alloc_anon_noexit, (void *) MB(1));
1216 
1217 	if (!cg_run(child, alloc_anon, (void *)MB(100)))
1218 		goto cleanup;
1219 
1220 	if (cg_test_proc_killed(child))
1221 		goto cleanup;
1222 	if (cg_test_proc_killed(parent))
1223 		goto cleanup;
1224 
1225 	ret = KSFT_PASS;
1226 
1227 cleanup:
1228 	if (child)
1229 		cg_destroy(child);
1230 	if (parent)
1231 		cg_destroy(parent);
1232 	free(child);
1233 	free(parent);
1234 
1235 	return ret;
1236 }
1237 
1238 /*
1239  * This test disables swapping and tries to allocate anonymous memory
1240  * up to OOM with memory.group.oom set. Then it checks that all
1241  * processes were killed except those set with OOM_SCORE_ADJ_MIN
1242  */
1243 static int test_memcg_oom_group_score_events(const char *root)
1244 {
1245 	int ret = KSFT_FAIL;
1246 	char *memcg;
1247 	int safe_pid;
1248 
1249 	memcg = cg_name(root, "memcg_test_0");
1250 
1251 	if (!memcg)
1252 		goto cleanup;
1253 
1254 	if (cg_create(memcg))
1255 		goto cleanup;
1256 
1257 	if (cg_write(memcg, "memory.max", "50M"))
1258 		goto cleanup;
1259 
1260 	if (cg_write(memcg, "memory.swap.max", "0"))
1261 		goto cleanup;
1262 
1263 	if (cg_write(memcg, "memory.oom.group", "1"))
1264 		goto cleanup;
1265 
1266 	safe_pid = cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(1));
1267 	if (set_oom_adj_score(safe_pid, OOM_SCORE_ADJ_MIN))
1268 		goto cleanup;
1269 
1270 	cg_run_nowait(memcg, alloc_anon_noexit, (void *) MB(1));
1271 	if (!cg_run(memcg, alloc_anon, (void *)MB(100)))
1272 		goto cleanup;
1273 
1274 	if (cg_read_key_long(memcg, "memory.events", "oom_kill ") != 3)
1275 		goto cleanup;
1276 
1277 	if (kill(safe_pid, SIGKILL))
1278 		goto cleanup;
1279 
1280 	ret = KSFT_PASS;
1281 
1282 cleanup:
1283 	if (memcg)
1284 		cg_destroy(memcg);
1285 	free(memcg);
1286 
1287 	return ret;
1288 }
1289 
1290 #define T(x) { x, #x }
1291 struct memcg_test {
1292 	int (*fn)(const char *root);
1293 	const char *name;
1294 } tests[] = {
1295 	T(test_memcg_subtree_control),
1296 	T(test_memcg_current),
1297 	T(test_memcg_min),
1298 	T(test_memcg_low),
1299 	T(test_memcg_high),
1300 	T(test_memcg_high_sync),
1301 	T(test_memcg_max),
1302 	T(test_memcg_reclaim),
1303 	T(test_memcg_oom_events),
1304 	T(test_memcg_swap_max),
1305 	T(test_memcg_sock),
1306 	T(test_memcg_oom_group_leaf_events),
1307 	T(test_memcg_oom_group_parent_events),
1308 	T(test_memcg_oom_group_score_events),
1309 };
1310 #undef T
1311 
1312 int main(int argc, char **argv)
1313 {
1314 	char root[PATH_MAX];
1315 	int i, proc_status, ret = EXIT_SUCCESS;
1316 
1317 	if (cg_find_unified_root(root, sizeof(root), NULL))
1318 		ksft_exit_skip("cgroup v2 isn't mounted\n");
1319 
1320 	/*
1321 	 * Check that memory controller is available:
1322 	 * memory is listed in cgroup.controllers
1323 	 */
1324 	if (cg_read_strstr(root, "cgroup.controllers", "memory"))
1325 		ksft_exit_skip("memory controller isn't available\n");
1326 
1327 	if (cg_read_strstr(root, "cgroup.subtree_control", "memory"))
1328 		if (cg_write(root, "cgroup.subtree_control", "+memory"))
1329 			ksft_exit_skip("Failed to set memory controller\n");
1330 
1331 	proc_status = proc_mount_contains("memory_recursiveprot");
1332 	if (proc_status < 0)
1333 		ksft_exit_skip("Failed to query cgroup mount option\n");
1334 	has_recursiveprot = proc_status;
1335 
1336 	proc_status = proc_mount_contains("memory_localevents");
1337 	if (proc_status < 0)
1338 		ksft_exit_skip("Failed to query cgroup mount option\n");
1339 	has_localevents = proc_status;
1340 
1341 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
1342 		switch (tests[i].fn(root)) {
1343 		case KSFT_PASS:
1344 			ksft_test_result_pass("%s\n", tests[i].name);
1345 			break;
1346 		case KSFT_SKIP:
1347 			ksft_test_result_skip("%s\n", tests[i].name);
1348 			break;
1349 		default:
1350 			ret = EXIT_FAILURE;
1351 			ksft_test_result_fail("%s\n", tests[i].name);
1352 			break;
1353 		}
1354 	}
1355 
1356 	return ret;
1357 }
1358