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authorDavid Herrmann <dh.herrmann@gmail.com>2014-08-08 17:25:32 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-08 18:57:31 -0400
commit4f5ce5e8d7e2da3c714df8a7fa42edb9f992fc52 (patch)
tree6bdac69397a13f372a4466e7c629924433e619bb /tools/testing
parent9183df25fe7b194563db3fec6dc3202a5855839c (diff)
selftests: add memfd_create() + sealing tests
Some basic tests to verify sealing on memfds works as expected and guarantees the advertised semantics. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/testing')
-rw-r--r--tools/testing/selftests/Makefile1
-rw-r--r--tools/testing/selftests/memfd/.gitignore2
-rw-r--r--tools/testing/selftests/memfd/Makefile29
-rw-r--r--tools/testing/selftests/memfd/memfd_test.c913
4 files changed, 945 insertions, 0 deletions
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index d10f95ce2ea4..6fd2a4402069 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -2,6 +2,7 @@ TARGETS = breakpoints
2TARGETS += cpu-hotplug 2TARGETS += cpu-hotplug
3TARGETS += efivarfs 3TARGETS += efivarfs
4TARGETS += kcmp 4TARGETS += kcmp
5TARGETS += memfd
5TARGETS += memory-hotplug 6TARGETS += memory-hotplug
6TARGETS += mqueue 7TARGETS += mqueue
7TARGETS += net 8TARGETS += net
diff --git a/tools/testing/selftests/memfd/.gitignore b/tools/testing/selftests/memfd/.gitignore
new file mode 100644
index 000000000000..bcc8ee20c710
--- /dev/null
+++ b/tools/testing/selftests/memfd/.gitignore
@@ -0,0 +1,2 @@
1memfd_test
2memfd-test-file
diff --git a/tools/testing/selftests/memfd/Makefile b/tools/testing/selftests/memfd/Makefile
new file mode 100644
index 000000000000..36653b903140
--- /dev/null
+++ b/tools/testing/selftests/memfd/Makefile
@@ -0,0 +1,29 @@
1uname_M := $(shell uname -m 2>/dev/null || echo not)
2ARCH ?= $(shell echo $(uname_M) | sed -e s/i.86/i386/)
3ifeq ($(ARCH),i386)
4 ARCH := X86
5endif
6ifeq ($(ARCH),x86_64)
7 ARCH := X86
8endif
9
10CFLAGS += -I../../../../arch/x86/include/generated/uapi/
11CFLAGS += -I../../../../arch/x86/include/uapi/
12CFLAGS += -I../../../../include/uapi/
13CFLAGS += -I../../../../include/
14
15all:
16ifeq ($(ARCH),X86)
17 gcc $(CFLAGS) memfd_test.c -o memfd_test
18else
19 echo "Not an x86 target, can't build memfd selftest"
20endif
21
22run_tests: all
23ifeq ($(ARCH),X86)
24 gcc $(CFLAGS) memfd_test.c -o memfd_test
25endif
26 @./memfd_test || echo "memfd_test: [FAIL]"
27
28clean:
29 $(RM) memfd_test
diff --git a/tools/testing/selftests/memfd/memfd_test.c b/tools/testing/selftests/memfd/memfd_test.c
new file mode 100644
index 000000000000..3634c909b1b0
--- /dev/null
+++ b/tools/testing/selftests/memfd/memfd_test.c
@@ -0,0 +1,913 @@
1#define _GNU_SOURCE
2#define __EXPORTED_HEADERS__
3
4#include <errno.h>
5#include <inttypes.h>
6#include <limits.h>
7#include <linux/falloc.h>
8#include <linux/fcntl.h>
9#include <linux/memfd.h>
10#include <sched.h>
11#include <stdio.h>
12#include <stdlib.h>
13#include <signal.h>
14#include <string.h>
15#include <sys/mman.h>
16#include <sys/stat.h>
17#include <sys/syscall.h>
18#include <unistd.h>
19
20#define MFD_DEF_SIZE 8192
21#define STACK_SIZE 65535
22
23static int sys_memfd_create(const char *name,
24 unsigned int flags)
25{
26 return syscall(__NR_memfd_create, name, flags);
27}
28
29static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags)
30{
31 int r, fd;
32
33 fd = sys_memfd_create(name, flags);
34 if (fd < 0) {
35 printf("memfd_create(\"%s\", %u) failed: %m\n",
36 name, flags);
37 abort();
38 }
39
40 r = ftruncate(fd, sz);
41 if (r < 0) {
42 printf("ftruncate(%llu) failed: %m\n", (unsigned long long)sz);
43 abort();
44 }
45
46 return fd;
47}
48
49static void mfd_fail_new(const char *name, unsigned int flags)
50{
51 int r;
52
53 r = sys_memfd_create(name, flags);
54 if (r >= 0) {
55 printf("memfd_create(\"%s\", %u) succeeded, but failure expected\n",
56 name, flags);
57 close(r);
58 abort();
59 }
60}
61
62static __u64 mfd_assert_get_seals(int fd)
63{
64 long r;
65
66 r = fcntl(fd, F_GET_SEALS);
67 if (r < 0) {
68 printf("GET_SEALS(%d) failed: %m\n", fd);
69 abort();
70 }
71
72 return r;
73}
74
75static void mfd_assert_has_seals(int fd, __u64 seals)
76{
77 __u64 s;
78
79 s = mfd_assert_get_seals(fd);
80 if (s != seals) {
81 printf("%llu != %llu = GET_SEALS(%d)\n",
82 (unsigned long long)seals, (unsigned long long)s, fd);
83 abort();
84 }
85}
86
87static void mfd_assert_add_seals(int fd, __u64 seals)
88{
89 long r;
90 __u64 s;
91
92 s = mfd_assert_get_seals(fd);
93 r = fcntl(fd, F_ADD_SEALS, seals);
94 if (r < 0) {
95 printf("ADD_SEALS(%d, %llu -> %llu) failed: %m\n",
96 fd, (unsigned long long)s, (unsigned long long)seals);
97 abort();
98 }
99}
100
101static void mfd_fail_add_seals(int fd, __u64 seals)
102{
103 long r;
104 __u64 s;
105
106 r = fcntl(fd, F_GET_SEALS);
107 if (r < 0)
108 s = 0;
109 else
110 s = r;
111
112 r = fcntl(fd, F_ADD_SEALS, seals);
113 if (r >= 0) {
114 printf("ADD_SEALS(%d, %llu -> %llu) didn't fail as expected\n",
115 fd, (unsigned long long)s, (unsigned long long)seals);
116 abort();
117 }
118}
119
120static void mfd_assert_size(int fd, size_t size)
121{
122 struct stat st;
123 int r;
124
125 r = fstat(fd, &st);
126 if (r < 0) {
127 printf("fstat(%d) failed: %m\n", fd);
128 abort();
129 } else if (st.st_size != size) {
130 printf("wrong file size %lld, but expected %lld\n",
131 (long long)st.st_size, (long long)size);
132 abort();
133 }
134}
135
136static int mfd_assert_dup(int fd)
137{
138 int r;
139
140 r = dup(fd);
141 if (r < 0) {
142 printf("dup(%d) failed: %m\n", fd);
143 abort();
144 }
145
146 return r;
147}
148
149static void *mfd_assert_mmap_shared(int fd)
150{
151 void *p;
152
153 p = mmap(NULL,
154 MFD_DEF_SIZE,
155 PROT_READ | PROT_WRITE,
156 MAP_SHARED,
157 fd,
158 0);
159 if (p == MAP_FAILED) {
160 printf("mmap() failed: %m\n");
161 abort();
162 }
163
164 return p;
165}
166
167static void *mfd_assert_mmap_private(int fd)
168{
169 void *p;
170
171 p = mmap(NULL,
172 MFD_DEF_SIZE,
173 PROT_READ,
174 MAP_PRIVATE,
175 fd,
176 0);
177 if (p == MAP_FAILED) {
178 printf("mmap() failed: %m\n");
179 abort();
180 }
181
182 return p;
183}
184
185static int mfd_assert_open(int fd, int flags, mode_t mode)
186{
187 char buf[512];
188 int r;
189
190 sprintf(buf, "/proc/self/fd/%d", fd);
191 r = open(buf, flags, mode);
192 if (r < 0) {
193 printf("open(%s) failed: %m\n", buf);
194 abort();
195 }
196
197 return r;
198}
199
200static void mfd_fail_open(int fd, int flags, mode_t mode)
201{
202 char buf[512];
203 int r;
204
205 sprintf(buf, "/proc/self/fd/%d", fd);
206 r = open(buf, flags, mode);
207 if (r >= 0) {
208 printf("open(%s) didn't fail as expected\n");
209 abort();
210 }
211}
212
213static void mfd_assert_read(int fd)
214{
215 char buf[16];
216 void *p;
217 ssize_t l;
218
219 l = read(fd, buf, sizeof(buf));
220 if (l != sizeof(buf)) {
221 printf("read() failed: %m\n");
222 abort();
223 }
224
225 /* verify PROT_READ *is* allowed */
226 p = mmap(NULL,
227 MFD_DEF_SIZE,
228 PROT_READ,
229 MAP_PRIVATE,
230 fd,
231 0);
232 if (p == MAP_FAILED) {
233 printf("mmap() failed: %m\n");
234 abort();
235 }
236 munmap(p, MFD_DEF_SIZE);
237
238 /* verify MAP_PRIVATE is *always* allowed (even writable) */
239 p = mmap(NULL,
240 MFD_DEF_SIZE,
241 PROT_READ | PROT_WRITE,
242 MAP_PRIVATE,
243 fd,
244 0);
245 if (p == MAP_FAILED) {
246 printf("mmap() failed: %m\n");
247 abort();
248 }
249 munmap(p, MFD_DEF_SIZE);
250}
251
252static void mfd_assert_write(int fd)
253{
254 ssize_t l;
255 void *p;
256 int r;
257
258 /* verify write() succeeds */
259 l = write(fd, "\0\0\0\0", 4);
260 if (l != 4) {
261 printf("write() failed: %m\n");
262 abort();
263 }
264
265 /* verify PROT_READ | PROT_WRITE is allowed */
266 p = mmap(NULL,
267 MFD_DEF_SIZE,
268 PROT_READ | PROT_WRITE,
269 MAP_SHARED,
270 fd,
271 0);
272 if (p == MAP_FAILED) {
273 printf("mmap() failed: %m\n");
274 abort();
275 }
276 *(char *)p = 0;
277 munmap(p, MFD_DEF_SIZE);
278
279 /* verify PROT_WRITE is allowed */
280 p = mmap(NULL,
281 MFD_DEF_SIZE,
282 PROT_WRITE,
283 MAP_SHARED,
284 fd,
285 0);
286 if (p == MAP_FAILED) {
287 printf("mmap() failed: %m\n");
288 abort();
289 }
290 *(char *)p = 0;
291 munmap(p, MFD_DEF_SIZE);
292
293 /* verify PROT_READ with MAP_SHARED is allowed and a following
294 * mprotect(PROT_WRITE) allows writing */
295 p = mmap(NULL,
296 MFD_DEF_SIZE,
297 PROT_READ,
298 MAP_SHARED,
299 fd,
300 0);
301 if (p == MAP_FAILED) {
302 printf("mmap() failed: %m\n");
303 abort();
304 }
305
306 r = mprotect(p, MFD_DEF_SIZE, PROT_READ | PROT_WRITE);
307 if (r < 0) {
308 printf("mprotect() failed: %m\n");
309 abort();
310 }
311
312 *(char *)p = 0;
313 munmap(p, MFD_DEF_SIZE);
314
315 /* verify PUNCH_HOLE works */
316 r = fallocate(fd,
317 FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
318 0,
319 MFD_DEF_SIZE);
320 if (r < 0) {
321 printf("fallocate(PUNCH_HOLE) failed: %m\n");
322 abort();
323 }
324}
325
326static void mfd_fail_write(int fd)
327{
328 ssize_t l;
329 void *p;
330 int r;
331
332 /* verify write() fails */
333 l = write(fd, "data", 4);
334 if (l != -EPERM) {
335 printf("expected EPERM on write(), but got %d: %m\n", (int)l);
336 abort();
337 }
338
339 /* verify PROT_READ | PROT_WRITE is not allowed */
340 p = mmap(NULL,
341 MFD_DEF_SIZE,
342 PROT_READ | PROT_WRITE,
343 MAP_SHARED,
344 fd,
345 0);
346 if (p != MAP_FAILED) {
347 printf("mmap() didn't fail as expected\n");
348 abort();
349 }
350
351 /* verify PROT_WRITE is not allowed */
352 p = mmap(NULL,
353 MFD_DEF_SIZE,
354 PROT_WRITE,
355 MAP_SHARED,
356 fd,
357 0);
358 if (p != MAP_FAILED) {
359 printf("mmap() didn't fail as expected\n");
360 abort();
361 }
362
363 /* Verify PROT_READ with MAP_SHARED with a following mprotect is not
364 * allowed. Note that for r/w the kernel already prevents the mmap. */
365 p = mmap(NULL,
366 MFD_DEF_SIZE,
367 PROT_READ,
368 MAP_SHARED,
369 fd,
370 0);
371 if (p != MAP_FAILED) {
372 r = mprotect(p, MFD_DEF_SIZE, PROT_READ | PROT_WRITE);
373 if (r >= 0) {
374 printf("mmap()+mprotect() didn't fail as expected\n");
375 abort();
376 }
377 }
378
379 /* verify PUNCH_HOLE fails */
380 r = fallocate(fd,
381 FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
382 0,
383 MFD_DEF_SIZE);
384 if (r >= 0) {
385 printf("fallocate(PUNCH_HOLE) didn't fail as expected\n");
386 abort();
387 }
388}
389
390static void mfd_assert_shrink(int fd)
391{
392 int r, fd2;
393
394 r = ftruncate(fd, MFD_DEF_SIZE / 2);
395 if (r < 0) {
396 printf("ftruncate(SHRINK) failed: %m\n");
397 abort();
398 }
399
400 mfd_assert_size(fd, MFD_DEF_SIZE / 2);
401
402 fd2 = mfd_assert_open(fd,
403 O_RDWR | O_CREAT | O_TRUNC,
404 S_IRUSR | S_IWUSR);
405 close(fd2);
406
407 mfd_assert_size(fd, 0);
408}
409
410static void mfd_fail_shrink(int fd)
411{
412 int r;
413
414 r = ftruncate(fd, MFD_DEF_SIZE / 2);
415 if (r >= 0) {
416 printf("ftruncate(SHRINK) didn't fail as expected\n");
417 abort();
418 }
419
420 mfd_fail_open(fd,
421 O_RDWR | O_CREAT | O_TRUNC,
422 S_IRUSR | S_IWUSR);
423}
424
425static void mfd_assert_grow(int fd)
426{
427 int r;
428
429 r = ftruncate(fd, MFD_DEF_SIZE * 2);
430 if (r < 0) {
431 printf("ftruncate(GROW) failed: %m\n");
432 abort();
433 }
434
435 mfd_assert_size(fd, MFD_DEF_SIZE * 2);
436
437 r = fallocate(fd,
438 0,
439 0,
440 MFD_DEF_SIZE * 4);
441 if (r < 0) {
442 printf("fallocate(ALLOC) failed: %m\n");
443 abort();
444 }
445
446 mfd_assert_size(fd, MFD_DEF_SIZE * 4);
447}
448
449static void mfd_fail_grow(int fd)
450{
451 int r;
452
453 r = ftruncate(fd, MFD_DEF_SIZE * 2);
454 if (r >= 0) {
455 printf("ftruncate(GROW) didn't fail as expected\n");
456 abort();
457 }
458
459 r = fallocate(fd,
460 0,
461 0,
462 MFD_DEF_SIZE * 4);
463 if (r >= 0) {
464 printf("fallocate(ALLOC) didn't fail as expected\n");
465 abort();
466 }
467}
468
469static void mfd_assert_grow_write(int fd)
470{
471 static char buf[MFD_DEF_SIZE * 8];
472 ssize_t l;
473
474 l = pwrite(fd, buf, sizeof(buf), 0);
475 if (l != sizeof(buf)) {
476 printf("pwrite() failed: %m\n");
477 abort();
478 }
479
480 mfd_assert_size(fd, MFD_DEF_SIZE * 8);
481}
482
483static void mfd_fail_grow_write(int fd)
484{
485 static char buf[MFD_DEF_SIZE * 8];
486 ssize_t l;
487
488 l = pwrite(fd, buf, sizeof(buf), 0);
489 if (l == sizeof(buf)) {
490 printf("pwrite() didn't fail as expected\n");
491 abort();
492 }
493}
494
495static int idle_thread_fn(void *arg)
496{
497 sigset_t set;
498 int sig;
499
500 /* dummy waiter; SIGTERM terminates us anyway */
501 sigemptyset(&set);
502 sigaddset(&set, SIGTERM);
503 sigwait(&set, &sig);
504
505 return 0;
506}
507
508static pid_t spawn_idle_thread(unsigned int flags)
509{
510 uint8_t *stack;
511 pid_t pid;
512
513 stack = malloc(STACK_SIZE);
514 if (!stack) {
515 printf("malloc(STACK_SIZE) failed: %m\n");
516 abort();
517 }
518
519 pid = clone(idle_thread_fn,
520 stack + STACK_SIZE,
521 SIGCHLD | flags,
522 NULL);
523 if (pid < 0) {
524 printf("clone() failed: %m\n");
525 abort();
526 }
527
528 return pid;
529}
530
531static void join_idle_thread(pid_t pid)
532{
533 kill(pid, SIGTERM);
534 waitpid(pid, NULL, 0);
535}
536
537/*
538 * Test memfd_create() syscall
539 * Verify syscall-argument validation, including name checks, flag validation
540 * and more.
541 */
542static void test_create(void)
543{
544 char buf[2048];
545 int fd;
546
547 /* test NULL name */
548 mfd_fail_new(NULL, 0);
549
550 /* test over-long name (not zero-terminated) */
551 memset(buf, 0xff, sizeof(buf));
552 mfd_fail_new(buf, 0);
553
554 /* test over-long zero-terminated name */
555 memset(buf, 0xff, sizeof(buf));
556 buf[sizeof(buf) - 1] = 0;
557 mfd_fail_new(buf, 0);
558
559 /* verify "" is a valid name */
560 fd = mfd_assert_new("", 0, 0);
561 close(fd);
562
563 /* verify invalid O_* open flags */
564 mfd_fail_new("", 0x0100);
565 mfd_fail_new("", ~MFD_CLOEXEC);
566 mfd_fail_new("", ~MFD_ALLOW_SEALING);
567 mfd_fail_new("", ~0);
568 mfd_fail_new("", 0x80000000U);
569
570 /* verify MFD_CLOEXEC is allowed */
571 fd = mfd_assert_new("", 0, MFD_CLOEXEC);
572 close(fd);
573
574 /* verify MFD_ALLOW_SEALING is allowed */
575 fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING);
576 close(fd);
577
578 /* verify MFD_ALLOW_SEALING | MFD_CLOEXEC is allowed */
579 fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING | MFD_CLOEXEC);
580 close(fd);
581}
582
583/*
584 * Test basic sealing
585 * A very basic sealing test to see whether setting/retrieving seals works.
586 */
587static void test_basic(void)
588{
589 int fd;
590
591 fd = mfd_assert_new("kern_memfd_basic",
592 MFD_DEF_SIZE,
593 MFD_CLOEXEC | MFD_ALLOW_SEALING);
594
595 /* add basic seals */
596 mfd_assert_has_seals(fd, 0);
597 mfd_assert_add_seals(fd, F_SEAL_SHRINK |
598 F_SEAL_WRITE);
599 mfd_assert_has_seals(fd, F_SEAL_SHRINK |
600 F_SEAL_WRITE);
601
602 /* add them again */
603 mfd_assert_add_seals(fd, F_SEAL_SHRINK |
604 F_SEAL_WRITE);
605 mfd_assert_has_seals(fd, F_SEAL_SHRINK |
606 F_SEAL_WRITE);
607
608 /* add more seals and seal against sealing */
609 mfd_assert_add_seals(fd, F_SEAL_GROW | F_SEAL_SEAL);
610 mfd_assert_has_seals(fd, F_SEAL_SHRINK |
611 F_SEAL_GROW |
612 F_SEAL_WRITE |
613 F_SEAL_SEAL);
614
615 /* verify that sealing no longer works */
616 mfd_fail_add_seals(fd, F_SEAL_GROW);
617 mfd_fail_add_seals(fd, 0);
618
619 close(fd);
620
621 /* verify sealing does not work without MFD_ALLOW_SEALING */
622 fd = mfd_assert_new("kern_memfd_basic",
623 MFD_DEF_SIZE,
624 MFD_CLOEXEC);
625 mfd_assert_has_seals(fd, F_SEAL_SEAL);
626 mfd_fail_add_seals(fd, F_SEAL_SHRINK |
627 F_SEAL_GROW |
628 F_SEAL_WRITE);
629 mfd_assert_has_seals(fd, F_SEAL_SEAL);
630 close(fd);
631}
632
633/*
634 * Test SEAL_WRITE
635 * Test whether SEAL_WRITE actually prevents modifications.
636 */
637static void test_seal_write(void)
638{
639 int fd;
640
641 fd = mfd_assert_new("kern_memfd_seal_write",
642 MFD_DEF_SIZE,
643 MFD_CLOEXEC | MFD_ALLOW_SEALING);
644 mfd_assert_has_seals(fd, 0);
645 mfd_assert_add_seals(fd, F_SEAL_WRITE);
646 mfd_assert_has_seals(fd, F_SEAL_WRITE);
647
648 mfd_assert_read(fd);
649 mfd_fail_write(fd);
650 mfd_assert_shrink(fd);
651 mfd_assert_grow(fd);
652 mfd_fail_grow_write(fd);
653
654 close(fd);
655}
656
657/*
658 * Test SEAL_SHRINK
659 * Test whether SEAL_SHRINK actually prevents shrinking
660 */
661static void test_seal_shrink(void)
662{
663 int fd;
664
665 fd = mfd_assert_new("kern_memfd_seal_shrink",
666 MFD_DEF_SIZE,
667 MFD_CLOEXEC | MFD_ALLOW_SEALING);
668 mfd_assert_has_seals(fd, 0);
669 mfd_assert_add_seals(fd, F_SEAL_SHRINK);
670 mfd_assert_has_seals(fd, F_SEAL_SHRINK);
671
672 mfd_assert_read(fd);
673 mfd_assert_write(fd);
674 mfd_fail_shrink(fd);
675 mfd_assert_grow(fd);
676 mfd_assert_grow_write(fd);
677
678 close(fd);
679}
680
681/*
682 * Test SEAL_GROW
683 * Test whether SEAL_GROW actually prevents growing
684 */
685static void test_seal_grow(void)
686{
687 int fd;
688
689 fd = mfd_assert_new("kern_memfd_seal_grow",
690 MFD_DEF_SIZE,
691 MFD_CLOEXEC | MFD_ALLOW_SEALING);
692 mfd_assert_has_seals(fd, 0);
693 mfd_assert_add_seals(fd, F_SEAL_GROW);
694 mfd_assert_has_seals(fd, F_SEAL_GROW);
695
696 mfd_assert_read(fd);
697 mfd_assert_write(fd);
698 mfd_assert_shrink(fd);
699 mfd_fail_grow(fd);
700 mfd_fail_grow_write(fd);
701
702 close(fd);
703}
704
705/*
706 * Test SEAL_SHRINK | SEAL_GROW
707 * Test whether SEAL_SHRINK | SEAL_GROW actually prevents resizing
708 */
709static void test_seal_resize(void)
710{
711 int fd;
712
713 fd = mfd_assert_new("kern_memfd_seal_resize",
714 MFD_DEF_SIZE,
715 MFD_CLOEXEC | MFD_ALLOW_SEALING);
716 mfd_assert_has_seals(fd, 0);
717 mfd_assert_add_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW);
718 mfd_assert_has_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW);
719
720 mfd_assert_read(fd);
721 mfd_assert_write(fd);
722 mfd_fail_shrink(fd);
723 mfd_fail_grow(fd);
724 mfd_fail_grow_write(fd);
725
726 close(fd);
727}
728
729/*
730 * Test sharing via dup()
731 * Test that seals are shared between dupped FDs and they're all equal.
732 */
733static void test_share_dup(void)
734{
735 int fd, fd2;
736
737 fd = mfd_assert_new("kern_memfd_share_dup",
738 MFD_DEF_SIZE,
739 MFD_CLOEXEC | MFD_ALLOW_SEALING);
740 mfd_assert_has_seals(fd, 0);
741
742 fd2 = mfd_assert_dup(fd);
743 mfd_assert_has_seals(fd2, 0);
744
745 mfd_assert_add_seals(fd, F_SEAL_WRITE);
746 mfd_assert_has_seals(fd, F_SEAL_WRITE);
747 mfd_assert_has_seals(fd2, F_SEAL_WRITE);
748
749 mfd_assert_add_seals(fd2, F_SEAL_SHRINK);
750 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
751 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK);
752
753 mfd_assert_add_seals(fd, F_SEAL_SEAL);
754 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
755 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
756
757 mfd_fail_add_seals(fd, F_SEAL_GROW);
758 mfd_fail_add_seals(fd2, F_SEAL_GROW);
759 mfd_fail_add_seals(fd, F_SEAL_SEAL);
760 mfd_fail_add_seals(fd2, F_SEAL_SEAL);
761
762 close(fd2);
763
764 mfd_fail_add_seals(fd, F_SEAL_GROW);
765 close(fd);
766}
767
768/*
769 * Test sealing with active mmap()s
770 * Modifying seals is only allowed if no other mmap() refs exist.
771 */
772static void test_share_mmap(void)
773{
774 int fd;
775 void *p;
776
777 fd = mfd_assert_new("kern_memfd_share_mmap",
778 MFD_DEF_SIZE,
779 MFD_CLOEXEC | MFD_ALLOW_SEALING);
780 mfd_assert_has_seals(fd, 0);
781
782 /* shared/writable ref prevents sealing WRITE, but allows others */
783 p = mfd_assert_mmap_shared(fd);
784 mfd_fail_add_seals(fd, F_SEAL_WRITE);
785 mfd_assert_has_seals(fd, 0);
786 mfd_assert_add_seals(fd, F_SEAL_SHRINK);
787 mfd_assert_has_seals(fd, F_SEAL_SHRINK);
788 munmap(p, MFD_DEF_SIZE);
789
790 /* readable ref allows sealing */
791 p = mfd_assert_mmap_private(fd);
792 mfd_assert_add_seals(fd, F_SEAL_WRITE);
793 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
794 munmap(p, MFD_DEF_SIZE);
795
796 close(fd);
797}
798
799/*
800 * Test sealing with open(/proc/self/fd/%d)
801 * Via /proc we can get access to a separate file-context for the same memfd.
802 * This is *not* like dup(), but like a real separate open(). Make sure the
803 * semantics are as expected and we correctly check for RDONLY / WRONLY / RDWR.
804 */
805static void test_share_open(void)
806{
807 int fd, fd2;
808
809 fd = mfd_assert_new("kern_memfd_share_open",
810 MFD_DEF_SIZE,
811 MFD_CLOEXEC | MFD_ALLOW_SEALING);
812 mfd_assert_has_seals(fd, 0);
813
814 fd2 = mfd_assert_open(fd, O_RDWR, 0);
815 mfd_assert_add_seals(fd, F_SEAL_WRITE);
816 mfd_assert_has_seals(fd, F_SEAL_WRITE);
817 mfd_assert_has_seals(fd2, F_SEAL_WRITE);
818
819 mfd_assert_add_seals(fd2, F_SEAL_SHRINK);
820 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
821 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK);
822
823 close(fd);
824 fd = mfd_assert_open(fd2, O_RDONLY, 0);
825
826 mfd_fail_add_seals(fd, F_SEAL_SEAL);
827 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
828 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK);
829
830 close(fd2);
831 fd2 = mfd_assert_open(fd, O_RDWR, 0);
832
833 mfd_assert_add_seals(fd2, F_SEAL_SEAL);
834 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
835 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
836
837 close(fd2);
838 close(fd);
839}
840
841/*
842 * Test sharing via fork()
843 * Test whether seal-modifications work as expected with forked childs.
844 */
845static void test_share_fork(void)
846{
847 int fd;
848 pid_t pid;
849
850 fd = mfd_assert_new("kern_memfd_share_fork",
851 MFD_DEF_SIZE,
852 MFD_CLOEXEC | MFD_ALLOW_SEALING);
853 mfd_assert_has_seals(fd, 0);
854
855 pid = spawn_idle_thread(0);
856 mfd_assert_add_seals(fd, F_SEAL_SEAL);
857 mfd_assert_has_seals(fd, F_SEAL_SEAL);
858
859 mfd_fail_add_seals(fd, F_SEAL_WRITE);
860 mfd_assert_has_seals(fd, F_SEAL_SEAL);
861
862 join_idle_thread(pid);
863
864 mfd_fail_add_seals(fd, F_SEAL_WRITE);
865 mfd_assert_has_seals(fd, F_SEAL_SEAL);
866
867 close(fd);
868}
869
870int main(int argc, char **argv)
871{
872 pid_t pid;
873
874 printf("memfd: CREATE\n");
875 test_create();
876 printf("memfd: BASIC\n");
877 test_basic();
878
879 printf("memfd: SEAL-WRITE\n");
880 test_seal_write();
881 printf("memfd: SEAL-SHRINK\n");
882 test_seal_shrink();
883 printf("memfd: SEAL-GROW\n");
884 test_seal_grow();
885 printf("memfd: SEAL-RESIZE\n");
886 test_seal_resize();
887
888 printf("memfd: SHARE-DUP\n");
889 test_share_dup();
890 printf("memfd: SHARE-MMAP\n");
891 test_share_mmap();
892 printf("memfd: SHARE-OPEN\n");
893 test_share_open();
894 printf("memfd: SHARE-FORK\n");
895 test_share_fork();
896
897 /* Run test-suite in a multi-threaded environment with a shared
898 * file-table. */
899 pid = spawn_idle_thread(CLONE_FILES | CLONE_FS | CLONE_VM);
900 printf("memfd: SHARE-DUP (shared file-table)\n");
901 test_share_dup();
902 printf("memfd: SHARE-MMAP (shared file-table)\n");
903 test_share_mmap();
904 printf("memfd: SHARE-OPEN (shared file-table)\n");
905 test_share_open();
906 printf("memfd: SHARE-FORK (shared file-table)\n");
907 test_share_fork();
908 join_idle_thread(pid);
909
910 printf("memfd: DONE\n");
911
912 return 0;
913}
generated by cgit v1.2.2 (git 2.25.0) at 2026-01-19 00:26:19 -0500