1 // SPDX-License-Identifier: GPL-2.0-or-later
2
3 #define _GNU_SOURCE
4
5 #include <assert.h>
6 #include <stddef.h>
7 #include <sched.h>
8 #include <fcntl.h>
9 #include <sys/param.h>
10 #include <sys/mount.h>
11 #include <sys/stat.h>
12 #include <sys/statfs.h>
13 #include <linux/stat.h>
14
15 #include "statmount.h"
16 #include "../../kselftest.h"
17
18 static const char *const known_fs[] = {
19 "9p", "adfs", "affs", "afs", "aio", "anon_inodefs", "apparmorfs",
20 "autofs", "bcachefs", "bdev", "befs", "bfs", "binder", "binfmt_misc",
21 "bpf", "btrfs", "btrfs_test_fs", "ceph", "cgroup", "cgroup2", "cifs",
22 "coda", "configfs", "cpuset", "cramfs", "cxl", "dax", "debugfs",
23 "devpts", "devtmpfs", "dmabuf", "drm", "ecryptfs", "efivarfs", "efs",
24 "erofs", "exfat", "ext2", "ext3", "ext4", "f2fs", "functionfs",
25 "fuse", "fuseblk", "fusectl", "gadgetfs", "gfs2", "gfs2meta", "hfs",
26 "hfsplus", "hostfs", "hpfs", "hugetlbfs", "ibmasmfs", "iomem",
27 "ipathfs", "iso9660", "jffs2", "jfs", "minix", "mqueue", "msdos",
28 "nfs", "nfs4", "nfsd", "nilfs2", "nsfs", "ntfs", "ntfs3", "ocfs2",
29 "ocfs2_dlmfs", "ocxlflash", "omfs", "openpromfs", "overlay", "pipefs",
30 "proc", "pstore", "pvfs2", "qnx4", "qnx6", "ramfs", "reiserfs",
31 "resctrl", "romfs", "rootfs", "rpc_pipefs", "s390_hypfs", "secretmem",
32 "securityfs", "selinuxfs", "smackfs", "smb3", "sockfs", "spufs",
33 "squashfs", "sysfs", "sysv", "tmpfs", "tracefs", "ubifs", "udf",
34 "ufs", "v7", "vboxsf", "vfat", "virtiofs", "vxfs", "xenfs", "xfs",
35 "zonefs", NULL };
36
statmount_alloc(uint64_t mnt_id,uint64_t mask,unsigned int flags)37 static struct statmount *statmount_alloc(uint64_t mnt_id, uint64_t mask, unsigned int flags)
38 {
39 size_t bufsize = 1 << 15;
40 struct statmount *buf = NULL, *tmp = alloca(bufsize);
41 int tofree = 0;
42 int ret;
43
44 for (;;) {
45 ret = statmount(mnt_id, 0, mask, tmp, bufsize, flags);
46 if (ret != -1)
47 break;
48 if (tofree)
49 free(tmp);
50 if (errno != EOVERFLOW)
51 return NULL;
52 bufsize <<= 1;
53 tofree = 1;
54 tmp = malloc(bufsize);
55 if (!tmp)
56 return NULL;
57 }
58 buf = malloc(tmp->size);
59 if (buf)
60 memcpy(buf, tmp, tmp->size);
61 if (tofree)
62 free(tmp);
63
64 return buf;
65 }
66
write_file(const char * path,const char * val)67 static void write_file(const char *path, const char *val)
68 {
69 int fd = open(path, O_WRONLY);
70 size_t len = strlen(val);
71 int ret;
72
73 if (fd == -1)
74 ksft_exit_fail_msg("opening %s for write: %s\n", path, strerror(errno));
75
76 ret = write(fd, val, len);
77 if (ret == -1)
78 ksft_exit_fail_msg("writing to %s: %s\n", path, strerror(errno));
79 if (ret != len)
80 ksft_exit_fail_msg("short write to %s\n", path);
81
82 ret = close(fd);
83 if (ret == -1)
84 ksft_exit_fail_msg("closing %s\n", path);
85 }
86
get_mnt_id(const char * name,const char * path,uint64_t mask)87 static uint64_t get_mnt_id(const char *name, const char *path, uint64_t mask)
88 {
89 struct statx sx;
90 int ret;
91
92 ret = statx(AT_FDCWD, path, 0, mask, &sx);
93 if (ret == -1)
94 ksft_exit_fail_msg("retrieving %s mount ID for %s: %s\n",
95 mask & STATX_MNT_ID_UNIQUE ? "unique" : "old",
96 name, strerror(errno));
97 if (!(sx.stx_mask & mask))
98 ksft_exit_fail_msg("no %s mount ID available for %s\n",
99 mask & STATX_MNT_ID_UNIQUE ? "unique" : "old",
100 name);
101
102 return sx.stx_mnt_id;
103 }
104
105
106 static char root_mntpoint[] = "/tmp/statmount_test_root.XXXXXX";
107 static int orig_root;
108 static uint64_t root_id, parent_id;
109 static uint32_t old_root_id, old_parent_id;
110 static FILE *f_mountinfo;
111
cleanup_namespace(void)112 static void cleanup_namespace(void)
113 {
114 int ret;
115
116 ret = fchdir(orig_root);
117 if (ret == -1)
118 ksft_perror("fchdir to original root");
119
120 ret = chroot(".");
121 if (ret == -1)
122 ksft_perror("chroot to original root");
123
124 umount2(root_mntpoint, MNT_DETACH);
125 rmdir(root_mntpoint);
126 }
127
setup_namespace(void)128 static void setup_namespace(void)
129 {
130 int ret;
131 char buf[32];
132 uid_t uid = getuid();
133 gid_t gid = getgid();
134
135 ret = unshare(CLONE_NEWNS|CLONE_NEWUSER|CLONE_NEWPID);
136 if (ret == -1)
137 ksft_exit_fail_msg("unsharing mountns and userns: %s\n",
138 strerror(errno));
139
140 sprintf(buf, "0 %d 1", uid);
141 write_file("/proc/self/uid_map", buf);
142 write_file("/proc/self/setgroups", "deny");
143 sprintf(buf, "0 %d 1", gid);
144 write_file("/proc/self/gid_map", buf);
145
146 f_mountinfo = fopen("/proc/self/mountinfo", "re");
147 if (!f_mountinfo)
148 ksft_exit_fail_msg("failed to open mountinfo: %s\n",
149 strerror(errno));
150
151 ret = mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
152 if (ret == -1)
153 ksft_exit_fail_msg("making mount tree private: %s\n",
154 strerror(errno));
155
156 if (!mkdtemp(root_mntpoint))
157 ksft_exit_fail_msg("creating temporary directory %s: %s\n",
158 root_mntpoint, strerror(errno));
159
160 old_parent_id = get_mnt_id("parent", root_mntpoint, STATX_MNT_ID);
161 parent_id = get_mnt_id("parent", root_mntpoint, STATX_MNT_ID_UNIQUE);
162
163 orig_root = open("/", O_PATH);
164 if (orig_root == -1)
165 ksft_exit_fail_msg("opening root directory: %s",
166 strerror(errno));
167
168 atexit(cleanup_namespace);
169
170 ret = mount(root_mntpoint, root_mntpoint, NULL, MS_BIND, NULL);
171 if (ret == -1)
172 ksft_exit_fail_msg("mounting temp root %s: %s\n",
173 root_mntpoint, strerror(errno));
174
175 ret = chroot(root_mntpoint);
176 if (ret == -1)
177 ksft_exit_fail_msg("chroot to temp root %s: %s\n",
178 root_mntpoint, strerror(errno));
179
180 ret = chdir("/");
181 if (ret == -1)
182 ksft_exit_fail_msg("chdir to root: %s\n", strerror(errno));
183
184 old_root_id = get_mnt_id("root", "/", STATX_MNT_ID);
185 root_id = get_mnt_id("root", "/", STATX_MNT_ID_UNIQUE);
186 }
187
setup_mount_tree(int log2_num)188 static int setup_mount_tree(int log2_num)
189 {
190 int ret, i;
191
192 ret = mount("", "/", NULL, MS_REC|MS_SHARED, NULL);
193 if (ret == -1) {
194 ksft_test_result_fail("making mount tree shared: %s\n",
195 strerror(errno));
196 return -1;
197 }
198
199 for (i = 0; i < log2_num; i++) {
200 ret = mount("/", "/", NULL, MS_BIND, NULL);
201 if (ret == -1) {
202 ksft_test_result_fail("mounting submount %s: %s\n",
203 root_mntpoint, strerror(errno));
204 return -1;
205 }
206 }
207 return 0;
208 }
209
test_listmount_empty_root(void)210 static void test_listmount_empty_root(void)
211 {
212 ssize_t res;
213 const unsigned int size = 32;
214 uint64_t list[size];
215
216 res = listmount(LSMT_ROOT, 0, 0, list, size, 0);
217 if (res == -1) {
218 ksft_test_result_fail("listmount: %s\n", strerror(errno));
219 return;
220 }
221 if (res != 1) {
222 ksft_test_result_fail("listmount result is %zi != 1\n", res);
223 return;
224 }
225
226 if (list[0] != root_id) {
227 ksft_test_result_fail("listmount ID doesn't match 0x%llx != 0x%llx\n",
228 (unsigned long long) list[0],
229 (unsigned long long) root_id);
230 return;
231 }
232
233 ksft_test_result_pass("listmount empty root\n");
234 }
235
test_statmount_zero_mask(void)236 static void test_statmount_zero_mask(void)
237 {
238 struct statmount sm;
239 int ret;
240
241 ret = statmount(root_id, 0, 0, &sm, sizeof(sm), 0);
242 if (ret == -1) {
243 ksft_test_result_fail("statmount zero mask: %s\n",
244 strerror(errno));
245 return;
246 }
247 if (sm.size != sizeof(sm)) {
248 ksft_test_result_fail("unexpected size: %u != %u\n",
249 sm.size, (uint32_t) sizeof(sm));
250 return;
251 }
252 if (sm.mask != 0) {
253 ksft_test_result_fail("unexpected mask: 0x%llx != 0x0\n",
254 (unsigned long long) sm.mask);
255 return;
256 }
257
258 ksft_test_result_pass("statmount zero mask\n");
259 }
260
test_statmount_mnt_basic(void)261 static void test_statmount_mnt_basic(void)
262 {
263 struct statmount sm;
264 int ret;
265 uint64_t mask = STATMOUNT_MNT_BASIC;
266
267 ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);
268 if (ret == -1) {
269 ksft_test_result_fail("statmount mnt basic: %s\n",
270 strerror(errno));
271 return;
272 }
273 if (sm.size != sizeof(sm)) {
274 ksft_test_result_fail("unexpected size: %u != %u\n",
275 sm.size, (uint32_t) sizeof(sm));
276 return;
277 }
278 if (sm.mask != mask) {
279 ksft_test_result_skip("statmount mnt basic unavailable\n");
280 return;
281 }
282
283 if (sm.mnt_id != root_id) {
284 ksft_test_result_fail("unexpected root ID: 0x%llx != 0x%llx\n",
285 (unsigned long long) sm.mnt_id,
286 (unsigned long long) root_id);
287 return;
288 }
289
290 if (sm.mnt_id_old != old_root_id) {
291 ksft_test_result_fail("unexpected old root ID: %u != %u\n",
292 sm.mnt_id_old, old_root_id);
293 return;
294 }
295
296 if (sm.mnt_parent_id != parent_id) {
297 ksft_test_result_fail("unexpected parent ID: 0x%llx != 0x%llx\n",
298 (unsigned long long) sm.mnt_parent_id,
299 (unsigned long long) parent_id);
300 return;
301 }
302
303 if (sm.mnt_parent_id_old != old_parent_id) {
304 ksft_test_result_fail("unexpected old parent ID: %u != %u\n",
305 sm.mnt_parent_id_old, old_parent_id);
306 return;
307 }
308
309 if (sm.mnt_propagation != MS_PRIVATE) {
310 ksft_test_result_fail("unexpected propagation: 0x%llx\n",
311 (unsigned long long) sm.mnt_propagation);
312 return;
313 }
314
315 ksft_test_result_pass("statmount mnt basic\n");
316 }
317
318
test_statmount_sb_basic(void)319 static void test_statmount_sb_basic(void)
320 {
321 struct statmount sm;
322 int ret;
323 uint64_t mask = STATMOUNT_SB_BASIC;
324 struct statx sx;
325 struct statfs sf;
326
327 ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);
328 if (ret == -1) {
329 ksft_test_result_fail("statmount sb basic: %s\n",
330 strerror(errno));
331 return;
332 }
333 if (sm.size != sizeof(sm)) {
334 ksft_test_result_fail("unexpected size: %u != %u\n",
335 sm.size, (uint32_t) sizeof(sm));
336 return;
337 }
338 if (sm.mask != mask) {
339 ksft_test_result_skip("statmount sb basic unavailable\n");
340 return;
341 }
342
343 ret = statx(AT_FDCWD, "/", 0, 0, &sx);
344 if (ret == -1) {
345 ksft_test_result_fail("stat root failed: %s\n",
346 strerror(errno));
347 return;
348 }
349
350 if (sm.sb_dev_major != sx.stx_dev_major ||
351 sm.sb_dev_minor != sx.stx_dev_minor) {
352 ksft_test_result_fail("unexpected sb dev %u:%u != %u:%u\n",
353 sm.sb_dev_major, sm.sb_dev_minor,
354 sx.stx_dev_major, sx.stx_dev_minor);
355 return;
356 }
357
358 ret = statfs("/", &sf);
359 if (ret == -1) {
360 ksft_test_result_fail("statfs root failed: %s\n",
361 strerror(errno));
362 return;
363 }
364
365 if (sm.sb_magic != sf.f_type) {
366 ksft_test_result_fail("unexpected sb magic: 0x%llx != 0x%lx\n",
367 (unsigned long long) sm.sb_magic,
368 sf.f_type);
369 return;
370 }
371
372 ksft_test_result_pass("statmount sb basic\n");
373 }
374
test_statmount_mnt_point(void)375 static void test_statmount_mnt_point(void)
376 {
377 struct statmount *sm;
378
379 sm = statmount_alloc(root_id, STATMOUNT_MNT_POINT, 0);
380 if (!sm) {
381 ksft_test_result_fail("statmount mount point: %s\n",
382 strerror(errno));
383 return;
384 }
385
386 if (strcmp(sm->str + sm->mnt_point, "/") != 0) {
387 ksft_test_result_fail("unexpected mount point: '%s' != '/'\n",
388 sm->str + sm->mnt_point);
389 goto out;
390 }
391 ksft_test_result_pass("statmount mount point\n");
392 out:
393 free(sm);
394 }
395
test_statmount_mnt_root(void)396 static void test_statmount_mnt_root(void)
397 {
398 struct statmount *sm;
399 const char *mnt_root, *last_dir, *last_root;
400
401 last_dir = strrchr(root_mntpoint, '/');
402 assert(last_dir);
403 last_dir++;
404
405 sm = statmount_alloc(root_id, STATMOUNT_MNT_ROOT, 0);
406 if (!sm) {
407 ksft_test_result_fail("statmount mount root: %s\n",
408 strerror(errno));
409 return;
410 }
411 mnt_root = sm->str + sm->mnt_root;
412 last_root = strrchr(mnt_root, '/');
413 if (last_root)
414 last_root++;
415 else
416 last_root = mnt_root;
417
418 if (strcmp(last_dir, last_root) != 0) {
419 ksft_test_result_fail("unexpected mount root last component: '%s' != '%s'\n",
420 last_root, last_dir);
421 goto out;
422 }
423 ksft_test_result_pass("statmount mount root\n");
424 out:
425 free(sm);
426 }
427
test_statmount_fs_type(void)428 static void test_statmount_fs_type(void)
429 {
430 struct statmount *sm;
431 const char *fs_type;
432 const char *const *s;
433
434 sm = statmount_alloc(root_id, STATMOUNT_FS_TYPE, 0);
435 if (!sm) {
436 ksft_test_result_fail("statmount fs type: %s\n",
437 strerror(errno));
438 return;
439 }
440 fs_type = sm->str + sm->fs_type;
441 for (s = known_fs; s != NULL; s++) {
442 if (strcmp(fs_type, *s) == 0)
443 break;
444 }
445 if (!s)
446 ksft_print_msg("unknown filesystem type: %s\n", fs_type);
447
448 ksft_test_result_pass("statmount fs type\n");
449 free(sm);
450 }
451
test_statmount_mnt_opts(void)452 static void test_statmount_mnt_opts(void)
453 {
454 struct statmount *sm;
455 const char *statmount_opts;
456 char *line = NULL;
457 size_t len = 0;
458
459 sm = statmount_alloc(root_id, STATMOUNT_MNT_BASIC | STATMOUNT_MNT_OPTS,
460 0);
461 if (!sm) {
462 ksft_test_result_fail("statmount mnt opts: %s\n",
463 strerror(errno));
464 return;
465 }
466
467 while (getline(&line, &len, f_mountinfo) != -1) {
468 int i;
469 char *p, *p2;
470 unsigned int old_mnt_id;
471
472 old_mnt_id = atoi(line);
473 if (old_mnt_id != sm->mnt_id_old)
474 continue;
475
476 for (p = line, i = 0; p && i < 5; i++)
477 p = strchr(p + 1, ' ');
478 if (!p)
479 continue;
480
481 p2 = strchr(p + 1, ' ');
482 if (!p2)
483 continue;
484 *p2 = '\0';
485 p = strchr(p2 + 1, '-');
486 if (!p)
487 continue;
488 for (p++, i = 0; p && i < 2; i++)
489 p = strchr(p + 1, ' ');
490 if (!p)
491 continue;
492 p++;
493
494 /* skip generic superblock options */
495 if (strncmp(p, "ro", 2) == 0)
496 p += 2;
497 else if (strncmp(p, "rw", 2) == 0)
498 p += 2;
499 if (*p == ',')
500 p++;
501 if (strncmp(p, "sync", 4) == 0)
502 p += 4;
503 if (*p == ',')
504 p++;
505 if (strncmp(p, "dirsync", 7) == 0)
506 p += 7;
507 if (*p == ',')
508 p++;
509 if (strncmp(p, "lazytime", 8) == 0)
510 p += 8;
511 if (*p == ',')
512 p++;
513 p2 = strrchr(p, '\n');
514 if (p2)
515 *p2 = '\0';
516
517 statmount_opts = sm->str + sm->mnt_opts;
518 if (strcmp(statmount_opts, p) != 0)
519 ksft_test_result_fail(
520 "unexpected mount options: '%s' != '%s'\n",
521 statmount_opts, p);
522 else
523 ksft_test_result_pass("statmount mount options\n");
524 free(sm);
525 free(line);
526 return;
527 }
528
529 ksft_test_result_fail("didnt't find mount entry\n");
530 free(sm);
531 free(line);
532 }
533
test_statmount_string(uint64_t mask,size_t off,const char * name)534 static void test_statmount_string(uint64_t mask, size_t off, const char *name)
535 {
536 struct statmount *sm;
537 size_t len, shortsize, exactsize;
538 uint32_t start, i;
539 int ret;
540
541 sm = statmount_alloc(root_id, mask, 0);
542 if (!sm) {
543 ksft_test_result_fail("statmount %s: %s\n", name,
544 strerror(errno));
545 goto out;
546 }
547 if (sm->size < sizeof(*sm)) {
548 ksft_test_result_fail("unexpected size: %u < %u\n",
549 sm->size, (uint32_t) sizeof(*sm));
550 goto out;
551 }
552 if (sm->mask != mask) {
553 ksft_test_result_skip("statmount %s unavailable\n", name);
554 goto out;
555 }
556 len = sm->size - sizeof(*sm);
557 start = ((uint32_t *) sm)[off];
558
559 for (i = start;; i++) {
560 if (i >= len) {
561 ksft_test_result_fail("string out of bounds\n");
562 goto out;
563 }
564 if (!sm->str[i])
565 break;
566 }
567 exactsize = sm->size;
568 shortsize = sizeof(*sm) + i;
569
570 ret = statmount(root_id, 0, mask, sm, exactsize, 0);
571 if (ret == -1) {
572 ksft_test_result_fail("statmount exact size: %s\n",
573 strerror(errno));
574 goto out;
575 }
576 errno = 0;
577 ret = statmount(root_id, 0, mask, sm, shortsize, 0);
578 if (ret != -1 || errno != EOVERFLOW) {
579 ksft_test_result_fail("should have failed with EOVERFLOW: %s\n",
580 strerror(errno));
581 goto out;
582 }
583
584 ksft_test_result_pass("statmount string %s\n", name);
585 out:
586 free(sm);
587 }
588
test_listmount_tree(void)589 static void test_listmount_tree(void)
590 {
591 ssize_t res;
592 const unsigned int log2_num = 4;
593 const unsigned int step = 3;
594 const unsigned int size = (1 << log2_num) + step + 1;
595 size_t num, expect = 1 << log2_num;
596 uint64_t list[size];
597 uint64_t list2[size];
598 size_t i;
599
600
601 res = setup_mount_tree(log2_num);
602 if (res == -1)
603 return;
604
605 num = res = listmount(LSMT_ROOT, 0, 0, list, size, 0);
606 if (res == -1) {
607 ksft_test_result_fail("listmount: %s\n", strerror(errno));
608 return;
609 }
610 if (num != expect) {
611 ksft_test_result_fail("listmount result is %zi != %zi\n",
612 res, expect);
613 return;
614 }
615
616 for (i = 0; i < size - step;) {
617 res = listmount(LSMT_ROOT, 0, i ? list2[i - 1] : 0, list2 + i, step, 0);
618 if (res == -1)
619 ksft_test_result_fail("short listmount: %s\n",
620 strerror(errno));
621 i += res;
622 if (res < step)
623 break;
624 }
625 if (i != num) {
626 ksft_test_result_fail("different number of entries: %zu != %zu\n",
627 i, num);
628 return;
629 }
630 for (i = 0; i < num; i++) {
631 if (list2[i] != list[i]) {
632 ksft_test_result_fail("different value for entry %zu: 0x%llx != 0x%llx\n",
633 i,
634 (unsigned long long) list2[i],
635 (unsigned long long) list[i]);
636 }
637 }
638
639 ksft_test_result_pass("listmount tree\n");
640 }
641
642 #define str_off(memb) (offsetof(struct statmount, memb) / sizeof(uint32_t))
643
main(void)644 int main(void)
645 {
646 int ret;
647 uint64_t all_mask = STATMOUNT_SB_BASIC | STATMOUNT_MNT_BASIC |
648 STATMOUNT_PROPAGATE_FROM | STATMOUNT_MNT_ROOT |
649 STATMOUNT_MNT_POINT | STATMOUNT_FS_TYPE | STATMOUNT_MNT_NS_ID;
650
651 ksft_print_header();
652
653 ret = statmount(0, 0, 0, NULL, 0, 0);
654 assert(ret == -1);
655 if (errno == ENOSYS)
656 ksft_exit_skip("statmount() syscall not supported\n");
657
658 setup_namespace();
659
660 ksft_set_plan(15);
661 test_listmount_empty_root();
662 test_statmount_zero_mask();
663 test_statmount_mnt_basic();
664 test_statmount_sb_basic();
665 test_statmount_mnt_root();
666 test_statmount_mnt_point();
667 test_statmount_fs_type();
668 test_statmount_mnt_opts();
669 test_statmount_string(STATMOUNT_MNT_ROOT, str_off(mnt_root), "mount root");
670 test_statmount_string(STATMOUNT_MNT_POINT, str_off(mnt_point), "mount point");
671 test_statmount_string(STATMOUNT_FS_TYPE, str_off(fs_type), "fs type");
672 test_statmount_string(all_mask, str_off(mnt_root), "mount root & all");
673 test_statmount_string(all_mask, str_off(mnt_point), "mount point & all");
674 test_statmount_string(all_mask, str_off(fs_type), "fs type & all");
675
676 test_listmount_tree();
677
678
679 if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
680 ksft_exit_fail();
681 else
682 ksft_exit_pass();
683 }
684