summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/vm/mlock2-tests.c
blob: 4431994aade2ef6f3b55a67692997d632b8f168e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
#include <sys/mman.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <syscall.h>
#include <errno.h>
#include <stdbool.h>

#ifndef MLOCK_ONFAULT
#define MLOCK_ONFAULT 1
#endif

#ifndef MCL_ONFAULT
#define MCL_ONFAULT (MCL_FUTURE << 1)
#endif

static int mlock2_(void *start, size_t len, int flags)
{
#ifdef __NR_mlock2
	return syscall(__NR_mlock2, start, len, flags);
#else
	errno = ENOSYS;
	return -1;
#endif
}

struct vm_boundaries {
	unsigned long start;
	unsigned long end;
};

static int get_vm_area(unsigned long addr, struct vm_boundaries *area)
{
	FILE *file;
	int ret = 1;
	char line[1024] = {0};
	char *end_addr;
	char *stop;
	unsigned long start;
	unsigned long end;

	if (!area)
		return ret;

	file = fopen("/proc/self/maps", "r");
	if (!file) {
		perror("fopen");
		return ret;
	}

	memset(area, 0, sizeof(struct vm_boundaries));

	while(fgets(line, 1024, file)) {
		end_addr = strchr(line, '-');
		if (!end_addr) {
			printf("cannot parse /proc/self/maps\n");
			goto out;
		}
		*end_addr = '\0';
		end_addr++;
		stop = strchr(end_addr, ' ');
		if (!stop) {
			printf("cannot parse /proc/self/maps\n");
			goto out;
		}
		stop = '\0';

		sscanf(line, "%lx", &start);
		sscanf(end_addr, "%lx", &end);

		if (start <= addr && end > addr) {
			area->start = start;
			area->end = end;
			ret = 0;
			goto out;
		}
	}
out:
	fclose(file);
	return ret;
}

static uint64_t get_pageflags(unsigned long addr)
{
	FILE *file;
	uint64_t pfn;
	unsigned long offset;

	file = fopen("/proc/self/pagemap", "r");
	if (!file) {
		perror("fopen pagemap");
		_exit(1);
	}

	offset = addr / getpagesize() * sizeof(pfn);

	if (fseek(file, offset, SEEK_SET)) {
		perror("fseek pagemap");
		_exit(1);
	}

	if (fread(&pfn, sizeof(pfn), 1, file) != 1) {
		perror("fread pagemap");
		_exit(1);
	}

	fclose(file);
	return pfn;
}

static uint64_t get_kpageflags(unsigned long pfn)
{
	uint64_t flags;
	FILE *file;

	file = fopen("/proc/kpageflags", "r");
	if (!file) {
		perror("fopen kpageflags");
		_exit(1);
	}

	if (fseek(file, pfn * sizeof(flags), SEEK_SET)) {
		perror("fseek kpageflags");
		_exit(1);
	}

	if (fread(&flags, sizeof(flags), 1, file) != 1) {
		perror("fread kpageflags");
		_exit(1);
	}

	fclose(file);
	return flags;
}

static FILE *seek_to_smaps_entry(unsigned long addr)
{
	FILE *file;
	char *line = NULL;
	size_t size = 0;
	unsigned long start, end;
	char perms[5];
	unsigned long offset;
	char dev[32];
	unsigned long inode;
	char path[BUFSIZ];

	file = fopen("/proc/self/smaps", "r");
	if (!file) {
		perror("fopen smaps");
		_exit(1);
	}

	while (getline(&line, &size, file) > 0) {
		if (sscanf(line, "%lx-%lx %s %lx %s %lu %s\n",
			   &start, &end, perms, &offset, dev, &inode, path) < 6)
			goto next;

		if (start <= addr && addr < end)
			goto out;

next:
		free(line);
		line = NULL;
		size = 0;
	}

	fclose(file);
	file = NULL;

out:
	free(line);
	return file;
}

#define VMFLAGS "VmFlags:"

static bool is_vmflag_set(unsigned long addr, const char *vmflag)
{
	char *line = NULL;
	char *flags;
	size_t size = 0;
	bool ret = false;
	FILE *smaps;

	smaps = seek_to_smaps_entry(addr);
	if (!smaps) {
		printf("Unable to parse /proc/self/smaps\n");
		goto out;
	}

	while (getline(&line, &size, smaps) > 0) {
		if (!strstr(line, VMFLAGS)) {
			free(line);
			line = NULL;
			size = 0;
			continue;
		}

		flags = line + strlen(VMFLAGS);
		ret = (strstr(flags, vmflag) != NULL);
		goto out;
	}

out:
	free(line);
	fclose(smaps);
	return ret;
}

#define SIZE "Size:"
#define RSS  "Rss:"
#define LOCKED "lo"

static bool is_vma_lock_on_fault(unsigned long addr)
{
	bool ret = false;
	bool locked;
	FILE *smaps = NULL;
	unsigned long vma_size, vma_rss;
	char *line = NULL;
	char *value;
	size_t size = 0;

	locked = is_vmflag_set(addr, LOCKED);
	if (!locked)
		goto out;

	smaps = seek_to_smaps_entry(addr);
	if (!smaps) {
		printf("Unable to parse /proc/self/smaps\n");
		goto out;
	}

	while (getline(&line, &size, smaps) > 0) {
		if (!strstr(line, SIZE)) {
			free(line);
			line = NULL;
			size = 0;
			continue;
		}

		value = line + strlen(SIZE);
		if (sscanf(value, "%lu kB", &vma_size) < 1) {
			printf("Unable to parse smaps entry for Size\n");
			goto out;
		}
		break;
	}

	while (getline(&line, &size, smaps) > 0) {
		if (!strstr(line, RSS)) {
			free(line);
			line = NULL;
			size = 0;
			continue;
		}

		value = line + strlen(RSS);
		if (sscanf(value, "%lu kB", &vma_rss) < 1) {
			printf("Unable to parse smaps entry for Rss\n");
			goto out;
		}
		break;
	}

	ret = locked && (vma_rss < vma_size);
out:
	free(line);
	if (smaps)
		fclose(smaps);
	return ret;
}

#define PRESENT_BIT     0x8000000000000000
#define PFN_MASK        0x007FFFFFFFFFFFFF
#define UNEVICTABLE_BIT (1UL << 18)

static int lock_check(char *map)
{
	unsigned long page_size = getpagesize();
	uint64_t page1_flags, page2_flags;

	page1_flags = get_pageflags((unsigned long)map);
	page2_flags = get_pageflags((unsigned long)map + page_size);

	/* Both pages should be present */
	if (((page1_flags & PRESENT_BIT) == 0) ||
	    ((page2_flags & PRESENT_BIT) == 0)) {
		printf("Failed to make both pages present\n");
		return 1;
	}

	page1_flags = get_kpageflags(page1_flags & PFN_MASK);
	page2_flags = get_kpageflags(page2_flags & PFN_MASK);

	/* Both pages should be unevictable */
	if (((page1_flags & UNEVICTABLE_BIT) == 0) ||
	    ((page2_flags & UNEVICTABLE_BIT) == 0)) {
		printf("Failed to make both pages unevictable\n");
		return 1;
	}

	if (!is_vmflag_set((unsigned long)map, LOCKED)) {
		printf("VMA flag %s is missing on page 1\n", LOCKED);
		return 1;
	}

	if (!is_vmflag_set((unsigned long)map + page_size, LOCKED)) {
		printf("VMA flag %s is missing on page 2\n", LOCKED);
		return 1;
	}

	return 0;
}

static int unlock_lock_check(char *map)
{
	unsigned long page_size = getpagesize();
	uint64_t page1_flags, page2_flags;

	page1_flags = get_pageflags((unsigned long)map);
	page2_flags = get_pageflags((unsigned long)map + page_size);
	page1_flags = get_kpageflags(page1_flags & PFN_MASK);
	page2_flags = get_kpageflags(page2_flags & PFN_MASK);

	if ((page1_flags & UNEVICTABLE_BIT) || (page2_flags & UNEVICTABLE_BIT)) {
		printf("A page is still marked unevictable after unlock\n");
		return 1;
	}

	if (is_vmflag_set((unsigned long)map, LOCKED)) {
		printf("VMA flag %s is present on page 1 after unlock\n", LOCKED);
		return 1;
	}

	if (is_vmflag_set((unsigned long)map + page_size, LOCKED)) {
		printf("VMA flag %s is present on page 2 after unlock\n", LOCKED);
		return 1;
	}

	return 0;
}

static int test_mlock_lock()
{
	char *map;
	int ret = 1;
	unsigned long page_size = getpagesize();

	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
	if (map == MAP_FAILED) {
		perror("test_mlock_locked mmap");
		goto out;
	}

	if (mlock2_(map, 2 * page_size, 0)) {
		if (errno == ENOSYS) {
			printf("Cannot call new mlock family, skipping test\n");
			_exit(0);
		}
		perror("mlock2(0)");
		goto unmap;
	}

	if (lock_check(map))
		goto unmap;

	/* Now unlock and recheck attributes */
	if (munlock(map, 2 * page_size)) {
		perror("munlock()");
		goto unmap;
	}

	ret = unlock_lock_check(map);

unmap:
	munmap(map, 2 * page_size);
out:
	return ret;
}

static int onfault_check(char *map)
{
	unsigned long page_size = getpagesize();
	uint64_t page1_flags, page2_flags;

	page1_flags = get_pageflags((unsigned long)map);
	page2_flags = get_pageflags((unsigned long)map + page_size);

	/* Neither page should be present */
	if ((page1_flags & PRESENT_BIT) || (page2_flags & PRESENT_BIT)) {
		printf("Pages were made present by MLOCK_ONFAULT\n");
		return 1;
	}

	*map = 'a';
	page1_flags = get_pageflags((unsigned long)map);
	page2_flags = get_pageflags((unsigned long)map + page_size);

	/* Only page 1 should be present */
	if ((page1_flags & PRESENT_BIT) == 0) {
		printf("Page 1 is not present after fault\n");
		return 1;
	} else if (page2_flags & PRESENT_BIT) {
		printf("Page 2 was made present\n");
		return 1;
	}

	page1_flags = get_kpageflags(page1_flags & PFN_MASK);

	/* Page 1 should be unevictable */
	if ((page1_flags & UNEVICTABLE_BIT) == 0) {
		printf("Failed to make faulted page unevictable\n");
		return 1;
	}

	if (!is_vma_lock_on_fault((unsigned long)map)) {
		printf("VMA is not marked for lock on fault\n");
		return 1;
	}

	if (!is_vma_lock_on_fault((unsigned long)map + page_size)) {
		printf("VMA is not marked for lock on fault\n");
		return 1;
	}

	return 0;
}

static int unlock_onfault_check(char *map)
{
	unsigned long page_size = getpagesize();
	uint64_t page1_flags;

	page1_flags = get_pageflags((unsigned long)map);
	page1_flags = get_kpageflags(page1_flags & PFN_MASK);

	if (page1_flags & UNEVICTABLE_BIT) {
		printf("Page 1 is still marked unevictable after unlock\n");
		return 1;
	}

	if (is_vma_lock_on_fault((unsigned long)map) ||
	    is_vma_lock_on_fault((unsigned long)map + page_size)) {
		printf("VMA is still lock on fault after unlock\n");
		return 1;
	}

	return 0;
}

static int test_mlock_onfault()
{
	char *map;
	int ret = 1;
	unsigned long page_size = getpagesize();

	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
	if (map == MAP_FAILED) {
		perror("test_mlock_locked mmap");
		goto out;
	}

	if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {
		if (errno == ENOSYS) {
			printf("Cannot call new mlock family, skipping test\n");
			_exit(0);
		}
		perror("mlock2(MLOCK_ONFAULT)");
		goto unmap;
	}

	if (onfault_check(map))
		goto unmap;

	/* Now unlock and recheck attributes */
	if (munlock(map, 2 * page_size)) {
		if (errno == ENOSYS) {
			printf("Cannot call new mlock family, skipping test\n");
			_exit(0);
		}
		perror("munlock()");
		goto unmap;
	}

	ret = unlock_onfault_check(map);
unmap:
	munmap(map, 2 * page_size);
out:
	return ret;
}

static int test_lock_onfault_of_present()
{
	char *map;
	int ret = 1;
	unsigned long page_size = getpagesize();
	uint64_t page1_flags, page2_flags;

	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
	if (map == MAP_FAILED) {
		perror("test_mlock_locked mmap");
		goto out;
	}

	*map = 'a';

	if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {
		if (errno == ENOSYS) {
			printf("Cannot call new mlock family, skipping test\n");
			_exit(0);
		}
		perror("mlock2(MLOCK_ONFAULT)");
		goto unmap;
	}

	page1_flags = get_pageflags((unsigned long)map);
	page2_flags = get_pageflags((unsigned long)map + page_size);
	page1_flags = get_kpageflags(page1_flags & PFN_MASK);
	page2_flags = get_kpageflags(page2_flags & PFN_MASK);

	/* Page 1 should be unevictable */
	if ((page1_flags & UNEVICTABLE_BIT) == 0) {
		printf("Failed to make present page unevictable\n");
		goto unmap;
	}

	if (!is_vma_lock_on_fault((unsigned long)map) ||
	    !is_vma_lock_on_fault((unsigned long)map + page_size)) {
		printf("VMA with present pages is not marked lock on fault\n");
		goto unmap;
	}
	ret = 0;
unmap:
	munmap(map, 2 * page_size);
out:
	return ret;
}

static int test_munlockall()
{
	char *map;
	int ret = 1;
	unsigned long page_size = getpagesize();

	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (map == MAP_FAILED) {
		perror("test_munlockall mmap");
		goto out;
	}

	if (mlockall(MCL_CURRENT)) {
		perror("mlockall(MCL_CURRENT)");
		goto out;
	}

	if (lock_check(map))
		goto unmap;

	if (munlockall()) {
		perror("munlockall()");
		goto unmap;
	}

	if (unlock_lock_check(map))
		goto unmap;

	munmap(map, 2 * page_size);

	map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);

	if (map == MAP_FAILED) {
		perror("test_munlockall second mmap");
		goto out;
	}

	if (mlockall(MCL_CURRENT | MCL_ONFAULT)) {
		perror("mlockall(MCL_CURRENT | MCL_ONFAULT)");
		goto unmap;
	}

	if (onfault_check(map))
		goto unmap;

	if (munlockall()) {
		perror("munlockall()");
		goto unmap;
	}

	if (unlock_onfault_check(map))
		goto unmap;

	if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
		perror("mlockall(MCL_CURRENT | MCL_FUTURE)");
		goto out;
	}

	if (lock_check(map))
		goto unmap;

	if (munlockall()) {
		perror("munlockall()");
		goto unmap;
	}

	ret = unlock_lock_check(map);

unmap:
	munmap(map, 2 * page_size);
out:
	munlockall();
	return ret;
}

static int test_vma_management(bool call_mlock)
{
	int ret = 1;
	void *map;
	unsigned long page_size = getpagesize();
	struct vm_boundaries page1;
	struct vm_boundaries page2;
	struct vm_boundaries page3;

	map = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE,
		   MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
	if (map == MAP_FAILED) {
		perror("mmap()");
		return ret;
	}

	if (call_mlock && mlock2_(map, 3 * page_size, MLOCK_ONFAULT)) {
		if (errno == ENOSYS) {
			printf("Cannot call new mlock family, skipping test\n");
			_exit(0);
		}
		perror("mlock(ONFAULT)\n");
		goto out;
	}

	if (get_vm_area((unsigned long)map, &page1) ||
	    get_vm_area((unsigned long)map + page_size, &page2) ||
	    get_vm_area((unsigned long)map + page_size * 2, &page3)) {
		printf("couldn't find mapping in /proc/self/maps\n");
		goto out;
	}

	/*
	 * Before we unlock a portion, we need to that all three pages are in
	 * the same VMA.  If they are not we abort this test (Note that this is
	 * not a failure)
	 */
	if (page1.start != page2.start || page2.start != page3.start) {
		printf("VMAs are not merged to start, aborting test\n");
		ret = 0;
		goto out;
	}

	if (munlock(map + page_size, page_size)) {
		perror("munlock()");
		goto out;
	}

	if (get_vm_area((unsigned long)map, &page1) ||
	    get_vm_area((unsigned long)map + page_size, &page2) ||
	    get_vm_area((unsigned long)map + page_size * 2, &page3)) {
		printf("couldn't find mapping in /proc/self/maps\n");
		goto out;
	}

	/* All three VMAs should be different */
	if (page1.start == page2.start || page2.start == page3.start) {
		printf("failed to split VMA for munlock\n");
		goto out;
	}

	/* Now unlock the first and third page and check the VMAs again */
	if (munlock(map, page_size * 3)) {
		perror("munlock()");
		goto out;
	}

	if (get_vm_area((unsigned long)map, &page1) ||
	    get_vm_area((unsigned long)map + page_size, &page2) ||
	    get_vm_area((unsigned long)map + page_size * 2, &page3)) {
		printf("couldn't find mapping in /proc/self/maps\n");
		goto out;
	}

	/* Now all three VMAs should be the same */
	if (page1.start != page2.start || page2.start != page3.start) {
		printf("failed to merge VMAs after munlock\n");
		goto out;
	}

	ret = 0;
out:
	munmap(map, 3 * page_size);
	return ret;
}

static int test_mlockall(int (test_function)(bool call_mlock))
{
	int ret = 1;

	if (mlockall(MCL_CURRENT | MCL_ONFAULT | MCL_FUTURE)) {
		perror("mlockall");
		return ret;
	}

	ret = test_function(false);
	munlockall();
	return ret;
}

int main(int argc, char **argv)
{
	int ret = 0;
	ret += test_mlock_lock();
	ret += test_mlock_onfault();
	ret += test_munlockall();
	ret += test_lock_onfault_of_present();
	ret += test_vma_management(true);
	ret += test_mlockall(test_vma_management);
	return ret;
}
OpenPOWER on IntegriCloud