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1// SPDX-License-Identifier: GPL-2.0
2#define _GNU_SOURCE
3#include <sys/mman.h>
4#include <stdint.h>
5#include <unistd.h>
6#include <string.h>
7#include <sys/time.h>
8#include <sys/resource.h>
9#include <stdbool.h>
10#include "mlock2.h"
11
12#include "../kselftest.h"
13
14struct vm_boundaries {
15 unsigned long start;
16 unsigned long end;
17};
18
19static int get_vm_area(unsigned long addr, struct vm_boundaries *area)
20{
21 FILE *file;
22 int ret = 1;
23 char line[1024] = {0};
24 char *end_addr;
25 char *stop;
26 unsigned long start;
27 unsigned long end;
28
29 if (!area)
30 return ret;
31
32 file = fopen("/proc/self/maps", "r");
33 if (!file) {
34 perror("fopen");
35 return ret;
36 }
37
38 memset(area, 0, sizeof(struct vm_boundaries));
39
40 while(fgets(line, 1024, file)) {
41 end_addr = strchr(line, '-');
42 if (!end_addr) {
43 printf("cannot parse /proc/self/maps\n");
44 goto out;
45 }
46 *end_addr = '\0';
47 end_addr++;
48 stop = strchr(end_addr, ' ');
49 if (!stop) {
50 printf("cannot parse /proc/self/maps\n");
51 goto out;
52 }
53 stop = '\0';
54
55 sscanf(line, "%lx", &start);
56 sscanf(end_addr, "%lx", &end);
57
58 if (start <= addr && end > addr) {
59 area->start = start;
60 area->end = end;
61 ret = 0;
62 goto out;
63 }
64 }
65out:
66 fclose(file);
67 return ret;
68}
69
70#define VMFLAGS "VmFlags:"
71
72static bool is_vmflag_set(unsigned long addr, const char *vmflag)
73{
74 char *line = NULL;
75 char *flags;
76 size_t size = 0;
77 bool ret = false;
78 FILE *smaps;
79
80 smaps = seek_to_smaps_entry(addr);
81 if (!smaps) {
82 printf("Unable to parse /proc/self/smaps\n");
83 goto out;
84 }
85
86 while (getline(&line, &size, smaps) > 0) {
87 if (!strstr(line, VMFLAGS)) {
88 free(line);
89 line = NULL;
90 size = 0;
91 continue;
92 }
93
94 flags = line + strlen(VMFLAGS);
95 ret = (strstr(flags, vmflag) != NULL);
96 goto out;
97 }
98
99out:
100 free(line);
101 fclose(smaps);
102 return ret;
103}
104
105#define SIZE "Size:"
106#define RSS "Rss:"
107#define LOCKED "lo"
108
109static unsigned long get_value_for_name(unsigned long addr, const char *name)
110{
111 char *line = NULL;
112 size_t size = 0;
113 char *value_ptr;
114 FILE *smaps = NULL;
115 unsigned long value = -1UL;
116
117 smaps = seek_to_smaps_entry(addr);
118 if (!smaps) {
119 printf("Unable to parse /proc/self/smaps\n");
120 goto out;
121 }
122
123 while (getline(&line, &size, smaps) > 0) {
124 if (!strstr(line, name)) {
125 free(line);
126 line = NULL;
127 size = 0;
128 continue;
129 }
130
131 value_ptr = line + strlen(name);
132 if (sscanf(value_ptr, "%lu kB", &value) < 1) {
133 printf("Unable to parse smaps entry for Size\n");
134 goto out;
135 }
136 break;
137 }
138
139out:
140 if (smaps)
141 fclose(smaps);
142 free(line);
143 return value;
144}
145
146static bool is_vma_lock_on_fault(unsigned long addr)
147{
148 bool locked;
149 unsigned long vma_size, vma_rss;
150
151 locked = is_vmflag_set(addr, LOCKED);
152 if (!locked)
153 return false;
154
155 vma_size = get_value_for_name(addr, SIZE);
156 vma_rss = get_value_for_name(addr, RSS);
157
158 /* only one page is faulted in */
159 return (vma_rss < vma_size);
160}
161
162#define PRESENT_BIT 0x8000000000000000ULL
163#define PFN_MASK 0x007FFFFFFFFFFFFFULL
164#define UNEVICTABLE_BIT (1UL << 18)
165
166static int lock_check(unsigned long addr)
167{
168 bool locked;
169 unsigned long vma_size, vma_rss;
170
171 locked = is_vmflag_set(addr, LOCKED);
172 if (!locked)
173 return false;
174
175 vma_size = get_value_for_name(addr, SIZE);
176 vma_rss = get_value_for_name(addr, RSS);
177
178 return (vma_rss == vma_size);
179}
180
181static int unlock_lock_check(char *map)
182{
183 if (is_vmflag_set((unsigned long)map, LOCKED)) {
184 printf("VMA flag %s is present on page 1 after unlock\n", LOCKED);
185 return 1;
186 }
187
188 return 0;
189}
190
191static int test_mlock_lock()
192{
193 char *map;
194 int ret = 1;
195 unsigned long page_size = getpagesize();
196
197 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
198 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
199 if (map == MAP_FAILED) {
200 perror("test_mlock_locked mmap");
201 goto out;
202 }
203
204 if (mlock2_(map, 2 * page_size, 0)) {
205 if (errno == ENOSYS) {
206 printf("Cannot call new mlock family, skipping test\n");
207 _exit(KSFT_SKIP);
208 }
209 perror("mlock2(0)");
210 goto unmap;
211 }
212
213 if (!lock_check((unsigned long)map))
214 goto unmap;
215
216 /* Now unlock and recheck attributes */
217 if (munlock(map, 2 * page_size)) {
218 perror("munlock()");
219 goto unmap;
220 }
221
222 ret = unlock_lock_check(map);
223
224unmap:
225 munmap(map, 2 * page_size);
226out:
227 return ret;
228}
229
230static int onfault_check(char *map)
231{
232 *map = 'a';
233 if (!is_vma_lock_on_fault((unsigned long)map)) {
234 printf("VMA is not marked for lock on fault\n");
235 return 1;
236 }
237
238 return 0;
239}
240
241static int unlock_onfault_check(char *map)
242{
243 unsigned long page_size = getpagesize();
244
245 if (is_vma_lock_on_fault((unsigned long)map) ||
246 is_vma_lock_on_fault((unsigned long)map + page_size)) {
247 printf("VMA is still lock on fault after unlock\n");
248 return 1;
249 }
250
251 return 0;
252}
253
254static int test_mlock_onfault()
255{
256 char *map;
257 int ret = 1;
258 unsigned long page_size = getpagesize();
259
260 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
261 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
262 if (map == MAP_FAILED) {
263 perror("test_mlock_locked mmap");
264 goto out;
265 }
266
267 if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {
268 if (errno == ENOSYS) {
269 printf("Cannot call new mlock family, skipping test\n");
270 _exit(KSFT_SKIP);
271 }
272 perror("mlock2(MLOCK_ONFAULT)");
273 goto unmap;
274 }
275
276 if (onfault_check(map))
277 goto unmap;
278
279 /* Now unlock and recheck attributes */
280 if (munlock(map, 2 * page_size)) {
281 if (errno == ENOSYS) {
282 printf("Cannot call new mlock family, skipping test\n");
283 _exit(KSFT_SKIP);
284 }
285 perror("munlock()");
286 goto unmap;
287 }
288
289 ret = unlock_onfault_check(map);
290unmap:
291 munmap(map, 2 * page_size);
292out:
293 return ret;
294}
295
296static int test_lock_onfault_of_present()
297{
298 char *map;
299 int ret = 1;
300 unsigned long page_size = getpagesize();
301
302 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
303 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
304 if (map == MAP_FAILED) {
305 perror("test_mlock_locked mmap");
306 goto out;
307 }
308
309 *map = 'a';
310
311 if (mlock2_(map, 2 * page_size, MLOCK_ONFAULT)) {
312 if (errno == ENOSYS) {
313 printf("Cannot call new mlock family, skipping test\n");
314 _exit(KSFT_SKIP);
315 }
316 perror("mlock2(MLOCK_ONFAULT)");
317 goto unmap;
318 }
319
320 if (!is_vma_lock_on_fault((unsigned long)map) ||
321 !is_vma_lock_on_fault((unsigned long)map + page_size)) {
322 printf("VMA with present pages is not marked lock on fault\n");
323 goto unmap;
324 }
325 ret = 0;
326unmap:
327 munmap(map, 2 * page_size);
328out:
329 return ret;
330}
331
332static int test_munlockall()
333{
334 char *map;
335 int ret = 1;
336 unsigned long page_size = getpagesize();
337
338 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
339 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
340
341 if (map == MAP_FAILED) {
342 perror("test_munlockall mmap");
343 goto out;
344 }
345
346 if (mlockall(MCL_CURRENT)) {
347 perror("mlockall(MCL_CURRENT)");
348 goto out;
349 }
350
351 if (!lock_check((unsigned long)map))
352 goto unmap;
353
354 if (munlockall()) {
355 perror("munlockall()");
356 goto unmap;
357 }
358
359 if (unlock_lock_check(map))
360 goto unmap;
361
362 munmap(map, 2 * page_size);
363
364 map = mmap(NULL, 2 * page_size, PROT_READ | PROT_WRITE,
365 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
366
367 if (map == MAP_FAILED) {
368 perror("test_munlockall second mmap");
369 goto out;
370 }
371
372 if (mlockall(MCL_CURRENT | MCL_ONFAULT)) {
373 perror("mlockall(MCL_CURRENT | MCL_ONFAULT)");
374 goto unmap;
375 }
376
377 if (onfault_check(map))
378 goto unmap;
379
380 if (munlockall()) {
381 perror("munlockall()");
382 goto unmap;
383 }
384
385 if (unlock_onfault_check(map))
386 goto unmap;
387
388 if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
389 perror("mlockall(MCL_CURRENT | MCL_FUTURE)");
390 goto out;
391 }
392
393 if (!lock_check((unsigned long)map))
394 goto unmap;
395
396 if (munlockall()) {
397 perror("munlockall()");
398 goto unmap;
399 }
400
401 ret = unlock_lock_check(map);
402
403unmap:
404 munmap(map, 2 * page_size);
405out:
406 munlockall();
407 return ret;
408}
409
410static int test_vma_management(bool call_mlock)
411{
412 int ret = 1;
413 void *map;
414 unsigned long page_size = getpagesize();
415 struct vm_boundaries page1;
416 struct vm_boundaries page2;
417 struct vm_boundaries page3;
418
419 map = mmap(NULL, 3 * page_size, PROT_READ | PROT_WRITE,
420 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
421 if (map == MAP_FAILED) {
422 perror("mmap()");
423 return ret;
424 }
425
426 if (call_mlock && mlock2_(map, 3 * page_size, MLOCK_ONFAULT)) {
427 if (errno == ENOSYS) {
428 printf("Cannot call new mlock family, skipping test\n");
429 _exit(KSFT_SKIP);
430 }
431 perror("mlock(ONFAULT)\n");
432 goto out;
433 }
434
435 if (get_vm_area((unsigned long)map, &page1) ||
436 get_vm_area((unsigned long)map + page_size, &page2) ||
437 get_vm_area((unsigned long)map + page_size * 2, &page3)) {
438 printf("couldn't find mapping in /proc/self/maps\n");
439 goto out;
440 }
441
442 /*
443 * Before we unlock a portion, we need to that all three pages are in
444 * the same VMA. If they are not we abort this test (Note that this is
445 * not a failure)
446 */
447 if (page1.start != page2.start || page2.start != page3.start) {
448 printf("VMAs are not merged to start, aborting test\n");
449 ret = 0;
450 goto out;
451 }
452
453 if (munlock(map + page_size, page_size)) {
454 perror("munlock()");
455 goto out;
456 }
457
458 if (get_vm_area((unsigned long)map, &page1) ||
459 get_vm_area((unsigned long)map + page_size, &page2) ||
460 get_vm_area((unsigned long)map + page_size * 2, &page3)) {
461 printf("couldn't find mapping in /proc/self/maps\n");
462 goto out;
463 }
464
465 /* All three VMAs should be different */
466 if (page1.start == page2.start || page2.start == page3.start) {
467 printf("failed to split VMA for munlock\n");
468 goto out;
469 }
470
471 /* Now unlock the first and third page and check the VMAs again */
472 if (munlock(map, page_size * 3)) {
473 perror("munlock()");
474 goto out;
475 }
476
477 if (get_vm_area((unsigned long)map, &page1) ||
478 get_vm_area((unsigned long)map + page_size, &page2) ||
479 get_vm_area((unsigned long)map + page_size * 2, &page3)) {
480 printf("couldn't find mapping in /proc/self/maps\n");
481 goto out;
482 }
483
484 /* Now all three VMAs should be the same */
485 if (page1.start != page2.start || page2.start != page3.start) {
486 printf("failed to merge VMAs after munlock\n");
487 goto out;
488 }
489
490 ret = 0;
491out:
492 munmap(map, 3 * page_size);
493 return ret;
494}
495
496static int test_mlockall(int (test_function)(bool call_mlock))
497{
498 int ret = 1;
499
500 if (mlockall(MCL_CURRENT | MCL_ONFAULT | MCL_FUTURE)) {
501 perror("mlockall");
502 return ret;
503 }
504
505 ret = test_function(false);
506 munlockall();
507 return ret;
508}
509
510int main(int argc, char **argv)
511{
512 int ret = 0;
513 ret += test_mlock_lock();
514 ret += test_mlock_onfault();
515 ret += test_munlockall();
516 ret += test_lock_onfault_of_present();
517 ret += test_vma_management(true);
518 ret += test_mlockall(test_vma_management);
519 return ret;
520}