1#define _GNU_SOURCE
2#include <sys/mman.h>
3#include <stdint.h>
4#include <unistd.h>
5#include <string.h>
6#include <sys/time.h>
7#include <sys/resource.h>
8#include <stdbool.h>
9#include "mlock2.h"
10
11struct vm_boundaries {
12 unsigned long start;
13 unsigned long end;
14};
15
16static int get_vm_area(unsigned long addr, struct vm_boundaries *area)
17{
18 FILE *file;
19 int ret = 1;
20 char line[1024] = {0};
21 char *end_addr;
22 char *stop;
23 unsigned long start;
24 unsigned long end;
25
26 if (!area)
27 return ret;
28
29 file = fopen("/proc/self/maps", "r");
30 if (!file) {
31 perror("fopen");
32 return ret;
33 }
34
35 memset(area, 0, sizeof(struct vm_boundaries));
36
37 while(fgets(line, 1024, file)) {
38 end_addr = strchr(line, '-');
39 if (!end_addr) {
40 printf("cannot parse /proc/self/maps\n");
41 goto out;
42 }
43 *end_addr = '\0';
44 end_addr++;
45 stop = strchr(end_addr, ' ');
46 if (!stop) {
47 printf("cannot parse /proc/self/maps\n");
48 goto out;
49 }
50 stop = '\0';
51
52 sscanf(line, "%lx", &start);
53 sscanf(end_addr, "%lx", &end);
54
55 if (start <= addr && end > addr) {
56 area->start = start;
57 area->end = end;
58 ret = 0;
59 goto out;
60 }
61 }
62out:
63 fclose(file);
64 return ret;
65}
66
67static uint64_t get_pageflags(unsigned long addr)
68{
69 FILE *file;
70 uint64_t pfn;
71 unsigned long offset;
72
73 file = fopen("/proc/self/pagemap", "r");
74 if (!file) {
75 perror("fopen pagemap");
76 _exit(1);
77 }
78
79 offset = addr / getpagesize() * sizeof(pfn);
80
81 if (fseek(file, offset, SEEK_SET)) {
82 perror("fseek pagemap");
83 _exit(1);
84 }
85
86 if (fread(&pfn, sizeof(pfn), 1, file) != 1) {
87 perror("fread pagemap");
88 _exit(1);
89 }
90
91 fclose(file);
92 return pfn;
93}
94
95static uint64_t get_kpageflags(unsigned long pfn)
96{
97 uint64_t flags;
98 FILE *file;
99
100 file = fopen("/proc/kpageflags", "r");
101 if (!file) {
102 perror("fopen kpageflags");
103 _exit(1);
104 }
105
106 if (fseek(file, pfn * sizeof(flags), SEEK_SET)) {
107 perror("fseek kpageflags");
108 _exit(1);
109 }
110
111 if (fread(&flags, sizeof(flags), 1, file) != 1) {
112 perror("fread kpageflags");
113 _exit(1);
114 }
115
116 fclose(file);
117 return flags;
118}
119
120#define VMFLAGS "VmFlags:"
121
122static bool is_vmflag_set(unsigned long addr, const char *vmflag)
123{
124 char *line = NULL;
125 char *flags;
126 size_t size = 0;
127 bool ret = false;
128 FILE *smaps;
129
130 smaps = seek_to_smaps_entry(addr);
131 if (!smaps) {
132 printf("Unable to parse /proc/self/smaps\n");
133 goto out;
134 }
135
136 while (getline(&line, &size, smaps) > 0) {
137 if (!strstr(line, VMFLAGS)) {
138 free(line);
139 line = NULL;
140 size = 0;
141 continue;
142 }
143
144 flags = line + strlen(VMFLAGS);
145 ret = (strstr(flags, vmflag) != NULL);
146 goto out;
147 }
148
149out:
150 free(line);
151 fclose(smaps);
152 return ret;
153}
154
155#define SIZE "Size:"
156#define RSS "Rss:"
157#define LOCKED "lo"
158
159static bool is_vma_lock_on_fault(unsigned long addr)
160{
161 bool ret = false;
162 bool locked;
163 FILE *smaps = NULL;
164 unsigned long vma_size, vma_rss;
165 char *line = NULL;
166 char *value;
167 size_t size = 0;
168
169 locked = is_vmflag_set(addr, LOCKED);
170 if (!locked)
171 goto out;
172
173 smaps = seek_to_smaps_entry(addr);
174 if (!smaps) {
175 printf("Unable to parse /proc/self/smaps\n");
176 goto out;
177 }
178
179 while (getline(&line, &size, smaps) > 0) {
180 if (!strstr(line, SIZE)) {
181 free(line);
182 line = NULL;
183 size = 0;
184 continue;
185 }
186
187 value = line + strlen(SIZE);
188 if (sscanf(value, "%lu kB", &vma_size) < 1) {
189 printf("Unable to parse smaps entry for Size\n");
190 goto out;
191 }
192 break;
193 }
194
195 while (getline(&line, &size, smaps) > 0) {
196 if (!strstr(line, RSS)) {
197 free(line);
198 line = NULL;
199 size = 0;
200 continue;
201 }
202
203 value = line + strlen(RSS);
204 if (sscanf(value, "%lu kB", &vma_rss) < 1) {
205 printf("Unable to parse smaps entry for Rss\n");
206 goto out;
207 }
208 break;
209 }
210
211 ret = locked && (vma_rss < vma_size);
212out:
213 free(line);
214 if (smaps)
215 fclose(smaps);
216 return ret;
217}
218
219#define PRESENT_BIT 0x8000000000000000ULL
220#define PFN_MASK 0x007FFFFFFFFFFFFFULL
221#define UNEVICTABLE_BIT (1UL << 18)
222
223static int lock_check(char *map)
224{
225 unsigned long page_size = getpagesize();
226 uint64_t page1_flags, page2_flags;
227
228 page1_flags = get_pageflags((unsigned long)map);
229 page2_flags = get_pageflags((unsigned long)map + page_size);
230
231
232 if (((page1_flags & PRESENT_BIT) == 0) ||
233 ((page2_flags & PRESENT_BIT) == 0)) {
234 printf("Failed to make both pages present\n");
235 return 1;
236 }
237
238 page1_flags = get_kpageflags(page1_flags & PFN_MASK);
239 page2_flags = get_kpageflags(page2_flags & PFN_MASK);
240
241
242 if (((page1_flags & UNEVICTABLE_BIT) == 0) ||
243 ((page2_flags & UNEVICTABLE_BIT) == 0)) {
244 printf("Failed to make both pages unevictable\n");
245 return 1;
246 }
247
248 if (!is_vmflag_set((unsigned long)map, LOCKED)) {
249 printf("VMA flag %s is missing on page 1\n", LOCKED);
250 return 1;
251 }
252
253 if (!is_vmflag_set((unsigned long)map + page_size, LOCKED)) {
254 printf("VMA flag %s is missing on page 2\n", LOCKED);
255 return 1;
256 }
257
258 return 0;
259}
260
261static int unlock_lock_check(char *map)
262{
263 unsigned long page_size = getpagesize();
264 uint64_t page1_flags, page2_flags;
265
266 page1_flags = get_pageflags((unsigned long)map);
267 page2_flags = get_pageflags((unsigned long)map + page_size);
268 page1_flags = get_kpageflags(page1_flags & PFN_MASK);
269 page2_flags = get_kpageflags(page2_flags & PFN_MASK);
270
271 if ((page1_flags & UNEVICTABLE_BIT) || (page2_flags & UNEVICTABLE_BIT)) {
272 printf("A page is still marked unevictable after unlock\n");
273 return 1;
274 }
275
276 if (is_vmflag_set((unsigned long)map, LOCKED)) {
277 printf("VMA flag %s is present on page 1 after unlock\n", LOCKED);
278 return 1;
279 }
280
281 if (is_vmflag_set((unsigned long)map + page_size, LOCKED)) {
282 printf("VMA flag %s is present on page 2 after unlock\n", LOCKED);
283 return 1;
284 }
285
286 return 0;
287}
288
289static int test_mlock_lock()
290{
291 char *map;
292 int ret = 1;
293 unsigned long page_size = getpagesize();
294
295 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
296 MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
297 if (map == MAP_FAILED) {
298 perror("test_mlock_locked mmap");
299 goto out;
300 }
301
302 if (mlock2_(map, 2 * page_size, 0)) {
303 if (errno == ENOSYS) {
304 printf("Cannot call new mlock family, skipping test\n");
305 _exit(0);
306 }
307 perror("mlock2(0)");
308 goto unmap;
309 }
310
311 if (lock_check(map))
312 goto unmap;
313
314
315 if (munlock(map, 2 * page_size)) {
316 perror("munlock()");
317 goto unmap;
318 }
319
320 ret = unlock_lock_check(map);
321
322unmap:
323 munmap(map, 2 * page_size);
324out:
325 return ret;
326}
327
328static int onfault_check(char *map)
329{
330 unsigned long page_size = getpagesize();
331 uint64_t page1_flags, page2_flags;
332
333 page1_flags = get_pageflags((unsigned long)map);
334 page2_flags = get_pageflags((unsigned long)map + page_size);
335
336
337 if ((page1_flags & PRESENT_BIT) || (page2_flags & PRESENT_BIT)) {
338 printf("Pages were made present by MLOCK_ONFAULT\n");
339 return 1;
340 }
341
342 *map = 'a';
343 page1_flags = get_pageflags((unsigned long)map);
344 page2_flags = get_pageflags((unsigned long)map + page_size);
345
346
347 if ((page1_flags & PRESENT_BIT) == 0) {
348 printf("Page 1 is not present after fault\n");
349 return 1;
350 } else if (page2_flags & PRESENT_BIT) {
351 printf("Page 2 was made present\n");
352 return 1;
353 }
354
355 page1_flags = get_kpageflags(page1_flags & PFN_MASK);
356
357
358 if ((page1_flags & UNEVICTABLE_BIT) == 0) {
359 printf("Failed to make faulted page unevictable\n");
360 return 1;
361 }
362
363 if (!is_vma_lock_on_fault((unsigned long)map)) {
364 printf("VMA is not marked for lock on fault\n");
365 return 1;
366 }
367
368 if (!is_vma_lock_on_fault((unsigned long)map + page_size)) {
369 printf("VMA is not marked for lock on fault\n");
370 return 1;
371 }
372
373 return 0;
374}
375
376static int unlock_onfault_check(char *map)
377{
378 unsigned long page_size = getpagesize();
379 uint64_t page1_flags;
380
381 page1_flags = get_pageflags((unsigned long)map);
382 page1_flags = get_kpageflags(page1_flags & PFN_MASK);
383
384 if (page1_flags & UNEVICTABLE_BIT) {
385 printf("Page 1 is still marked unevictable after unlock\n");
386 return 1;
387 }
388
389 if (is_vma_lock_on_fault((unsigned long)map) ||
390 is_vma_lock_on_fault((unsigned long)map + page_size)) {
391 printf("VMA is still lock on fault after unlock\n");
392 return 1;
393 }
394
395 return 0;
396}
397
398static int test_mlock_onfault()
399{
400 char *map;
401 int ret = 1;
402 unsigned long page_size = getpagesize();
403
404 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
405 MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
406 if (map == MAP_FAILED) {
407 perror("test_mlock_locked mmap");
408 goto out;
409 }
410
411 if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {
412 if (errno == ENOSYS) {
413 printf("Cannot call new mlock family, skipping test\n");
414 _exit(0);
415 }
416 perror("mlock2(MLOCK_ONFAULT)");
417 goto unmap;
418 }
419
420 if (onfault_check(map))
421 goto unmap;
422
423
424 if (munlock(map, 2 * page_size)) {
425 if (errno == ENOSYS) {
426 printf("Cannot call new mlock family, skipping test\n");
427 _exit(0);
428 }
429 perror("munlock()");
430 goto unmap;
431 }
432
433 ret = unlock_onfault_check(map);
434unmap:
435 munmap(map, 2 * page_size);
436out:
437 return ret;
438}
439
440static int test_lock_onfault_of_present()
441{
442 char *map;
443 int ret = 1;
444 unsigned long page_size = getpagesize();
445 uint64_t page1_flags, page2_flags;
446
447 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
448 MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
449 if (map == MAP_FAILED) {
450 perror("test_mlock_locked mmap");
451 goto out;
452 }
453
454 *map = 'a';
455
456 if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {
457 if (errno == ENOSYS) {
458 printf("Cannot call new mlock family, skipping test\n");
459 _exit(0);
460 }
461 perror("mlock2(MLOCK_ONFAULT)");
462 goto unmap;
463 }
464
465 page1_flags = get_pageflags((unsigned long)map);
466 page2_flags = get_pageflags((unsigned long)map + page_size);
467 page1_flags = get_kpageflags(page1_flags & PFN_MASK);
468 page2_flags = get_kpageflags(page2_flags & PFN_MASK);
469
470
471 if ((page1_flags & UNEVICTABLE_BIT) == 0) {
472 printf("Failed to make present page unevictable\n");
473 goto unmap;
474 }
475
476 if (!is_vma_lock_on_fault((unsigned long)map) ||
477 !is_vma_lock_on_fault((unsigned long)map + page_size)) {
478 printf("VMA with present pages is not marked lock on fault\n");
479 goto unmap;
480 }
481 ret = 0;
482unmap:
483 munmap(map, 2 * page_size);
484out:
485 return ret;
486}
487
488static int test_munlockall()
489{
490 char *map;
491 int ret = 1;
492 unsigned long page_size = getpagesize();
493
494 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
495 MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
496
497 if (map == MAP_FAILED) {
498 perror("test_munlockall mmap");
499 goto out;
500 }
501
502 if (mlockall(MCL_CURRENT)) {
503 perror("mlockall(MCL_CURRENT)");
504 goto out;
505 }
506
507 if (lock_check(map))
508 goto unmap;
509
510 if (munlockall()) {
511 perror("munlockall()");
512 goto unmap;
513 }
514
515 if (unlock_lock_check(map))
516 goto unmap;
517
518 munmap(map, 2 * page_size);
519
520 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
521 MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
522
523 if (map == MAP_FAILED) {
524 perror("test_munlockall second mmap");
525 goto out;
526 }
527
528 if (mlockall(MCL_CURRENT | MCL_ONFAULT)) {
529 perror("mlockall(MCL_CURRENT | MCL_ONFAULT)");
530 goto unmap;
531 }
532
533 if (onfault_check(map))
534 goto unmap;
535
536 if (munlockall()) {
537 perror("munlockall()");
538 goto unmap;
539 }
540
541 if (unlock_onfault_check(map))
542 goto unmap;
543
544 if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
545 perror("mlockall(MCL_CURRENT | MCL_FUTURE)");
546 goto out;
547 }
548
549 if (lock_check(map))
550 goto unmap;
551
552 if (munlockall()) {
553 perror("munlockall()");
554 goto unmap;
555 }
556
557 ret = unlock_lock_check(map);
558
559unmap:
560 munmap(map, 2 * page_size);
561out:
562 munlockall();
563 return ret;
564}
565
566static int test_vma_management(bool call_mlock)
567{
568 int ret = 1;
569 void *map;
570 unsigned long page_size = getpagesize();
571 struct vm_boundaries page1;
572 struct vm_boundaries page2;
573 struct vm_boundaries page3;
574
575 map = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE,
576 MAP_ANONYMOUS | MAP_PRIVATE, 0, 0);
577 if (map == MAP_FAILED) {
578 perror("mmap()");
579 return ret;
580 }
581
582 if (call_mlock && mlock2_(map, 3 * page_size, MLOCK_ONFAULT)) {
583 if (errno == ENOSYS) {
584 printf("Cannot call new mlock family, skipping test\n");
585 _exit(0);
586 }
587 perror("mlock(ONFAULT)\n");
588 goto out;
589 }
590
591 if (get_vm_area((unsigned long)map, &page1) ||
592 get_vm_area((unsigned long)map + page_size, &page2) ||
593 get_vm_area((unsigned long)map + page_size * 2, &page3)) {
594 printf("couldn't find mapping in /proc/self/maps\n");
595 goto out;
596 }
597
598
599
600
601
602
603 if (page1.start != page2.start || page2.start != page3.start) {
604 printf("VMAs are not merged to start, aborting test\n");
605 ret = 0;
606 goto out;
607 }
608
609 if (munlock(map + page_size, page_size)) {
610 perror("munlock()");
611 goto out;
612 }
613
614 if (get_vm_area((unsigned long)map, &page1) ||
615 get_vm_area((unsigned long)map + page_size, &page2) ||
616 get_vm_area((unsigned long)map + page_size * 2, &page3)) {
617 printf("couldn't find mapping in /proc/self/maps\n");
618 goto out;
619 }
620
621
622 if (page1.start == page2.start || page2.start == page3.start) {
623 printf("failed to split VMA for munlock\n");
624 goto out;
625 }
626
627
628 if (munlock(map, page_size * 3)) {
629 perror("munlock()");
630 goto out;
631 }
632
633 if (get_vm_area((unsigned long)map, &page1) ||
634 get_vm_area((unsigned long)map + page_size, &page2) ||
635 get_vm_area((unsigned long)map + page_size * 2, &page3)) {
636 printf("couldn't find mapping in /proc/self/maps\n");
637 goto out;
638 }
639
640
641 if (page1.start != page2.start || page2.start != page3.start) {
642 printf("failed to merge VMAs after munlock\n");
643 goto out;
644 }
645
646 ret = 0;
647out:
648 munmap(map, 3 * page_size);
649 return ret;
650}
651
652static int test_mlockall(int (test_function)(bool call_mlock))
653{
654 int ret = 1;
655
656 if (mlockall(MCL_CURRENT | MCL_ONFAULT | MCL_FUTURE)) {
657 perror("mlockall");
658 return ret;
659 }
660
661 ret = test_function(false);
662 munlockall();
663 return ret;
664}
665
666int main(int argc, char **argv)
667{
668 int ret = 0;
669 ret += test_mlock_lock();
670 ret += test_mlock_onfault();
671 ret += test_munlockall();
672 ret += test_lock_onfault_of_present();
673 ret += test_vma_management(true);
674 ret += test_mlockall(test_vma_management);
675 return ret;
676}
677
