1 /* $NetBSD: t_mmap.c,v 1.12 2017/01/16 16:31:05 christos Exp $ */
2 
3 /*-
4  * Copyright (c) 2011 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jukka Ruohonen.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*-
33  * Copyright (c)2004 YAMAMOTO Takashi,
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  */
57 #include <sys/cdefs.h>
58 __RCSID("$NetBSD: t_mmap.c,v 1.12 2017/01/16 16:31:05 christos Exp $");
59 
60 #include <sys/param.h>
61 #include <sys/disklabel.h>
62 #include <sys/mman.h>
63 #include <sys/stat.h>
64 #include <sys/socket.h>
65 #include <sys/sysctl.h>
66 #include <sys/wait.h>
67 
68 #include <atf-c.h>
69 #include <errno.h>
70 #include <fcntl.h>
71 #include <signal.h>
72 #include <stdio.h>
73 #include <stdlib.h>
74 #include <string.h>
75 #include <unistd.h>
76 #include <paths.h>
77 #ifdef __FreeBSD__
78 #include <stdint.h>
79 #endif
80 
81 static long	page = 0;
82 static char	path[] = "mmap";
83 static void	map_check(void *, int);
84 static void	map_sighandler(int);
85 static void	testloan(void *, void *, char, int);
86 
87 #define	BUFSIZE	(32 * 1024)	/* enough size to trigger sosend_loan */
88 
89 static void
90 map_check(void *map, int flag)
91 {
92 
93 	if (flag != 0) {
94 		ATF_REQUIRE(map == MAP_FAILED);
95 		return;
96 	}
97 
98 	ATF_REQUIRE(map != MAP_FAILED);
99 	ATF_REQUIRE(munmap(map, page) == 0);
100 }
101 
102 void
103 testloan(void *vp, void *vp2, char pat, int docheck)
104 {
105 	char buf[BUFSIZE];
106 	char backup[BUFSIZE];
107 	ssize_t nwritten;
108 	ssize_t nread;
109 	int fds[2];
110 	int val;
111 
112 	val = BUFSIZE;
113 
114 	if (docheck != 0)
115 		(void)memcpy(backup, vp, BUFSIZE);
116 
117 	if (socketpair(AF_LOCAL, SOCK_STREAM, PF_UNSPEC, fds) != 0)
118 		atf_tc_fail("socketpair() failed");
119 
120 	val = BUFSIZE;
121 
122 	if (setsockopt(fds[1], SOL_SOCKET, SO_RCVBUF, &val, sizeof(val)) != 0)
123 		atf_tc_fail("setsockopt() failed, SO_RCVBUF");
124 
125 	val = BUFSIZE;
126 
127 	if (setsockopt(fds[0], SOL_SOCKET, SO_SNDBUF, &val, sizeof(val)) != 0)
128 		atf_tc_fail("setsockopt() failed, SO_SNDBUF");
129 
130 	if (fcntl(fds[0], F_SETFL, O_NONBLOCK) != 0)
131 		atf_tc_fail("fcntl() failed");
132 
133 	nwritten = write(fds[0], (char *)vp + page, BUFSIZE - page);
134 
135 	if (nwritten == -1)
136 		atf_tc_fail("write() failed");
137 
138 	/* Break loan. */
139 	(void)memset(vp2, pat, BUFSIZE);
140 
141 	nread = read(fds[1], buf + page, BUFSIZE - page);
142 
143 	if (nread == -1)
144 		atf_tc_fail("read() failed");
145 
146 	if (nread != nwritten)
147 		atf_tc_fail("too short read");
148 
149 	if (docheck != 0 && memcmp(backup, buf + page, nread) != 0)
150 		atf_tc_fail("data mismatch");
151 
152 	ATF_REQUIRE(close(fds[0]) == 0);
153 	ATF_REQUIRE(close(fds[1]) == 0);
154 }
155 
156 static void
157 map_sighandler(int signo)
158 {
159 	_exit(signo);
160 }
161 
162 #ifdef __NetBSD__
163 ATF_TC(mmap_block);
164 ATF_TC_HEAD(mmap_block, tc)
165 {
166 	atf_tc_set_md_var(tc, "descr", "Test mmap(2) with a block device");
167 	atf_tc_set_md_var(tc, "require.user", "root");
168 }
169 
170 ATF_TC_BODY(mmap_block, tc)
171 {
172 	static const int mib[] = { CTL_HW, HW_DISKNAMES };
173 	static const unsigned int miblen = __arraycount(mib);
174 	char *map, *dk, *drives, dev[PATH_MAX];
175 	size_t len;
176 	int fd = -1;
177 
178 	atf_tc_skip("The test case causes a panic (PR kern/38889, kern/46592)");
179 
180 	ATF_REQUIRE(sysctl(mib, miblen, NULL, &len, NULL, 0) == 0);
181 	drives = malloc(len);
182 	ATF_REQUIRE(drives != NULL);
183 	ATF_REQUIRE(sysctl(mib, miblen, drives, &len, NULL, 0) == 0);
184 	for (dk = strtok(drives, " "); dk != NULL; dk = strtok(NULL, " ")) {
185 		sprintf(dev, _PATH_DEV "%s%c", dk, 'a'+RAW_PART);
186 		fprintf(stderr, "trying: %s\n", dev);
187 
188 		if ((fd = open(dev, O_RDONLY)) >= 0) {
189 			(void)fprintf(stderr, "using %s\n", dev);
190 			break;
191 		}
192 	}
193 	free(drives);
194 
195 	if (fd < 0)
196 		atf_tc_skip("failed to find suitable block device");
197 
198 	map = mmap(NULL, 4096, PROT_READ, MAP_FILE, fd, 0);
199 	ATF_REQUIRE(map != MAP_FAILED);
200 
201 	(void)fprintf(stderr, "first byte %x\n", *map);
202 	ATF_REQUIRE(close(fd) == 0);
203 	(void)fprintf(stderr, "first byte %x\n", *map);
204 
205 	ATF_REQUIRE(munmap(map, 4096) == 0);
206 }
207 #endif
208 
209 ATF_TC(mmap_err);
210 ATF_TC_HEAD(mmap_err, tc)
211 {
212 	atf_tc_set_md_var(tc, "descr", "Test error conditions of mmap(2)");
213 }
214 
215 ATF_TC_BODY(mmap_err, tc)
216 {
217 	size_t addr = SIZE_MAX;
218 	void *map;
219 
220 	errno = 0;
221 	map = mmap(NULL, 3, PROT_READ, MAP_FILE|MAP_PRIVATE, -1, 0);
222 
223 	ATF_REQUIRE(map == MAP_FAILED);
224 	ATF_REQUIRE(errno == EBADF);
225 
226 	errno = 0;
227 	map = mmap(&addr, page, PROT_READ, MAP_FIXED|MAP_PRIVATE, -1, 0);
228 
229 	ATF_REQUIRE(map == MAP_FAILED);
230 	ATF_REQUIRE(errno == EINVAL);
231 
232 	errno = 0;
233 	map = mmap(NULL, page, PROT_READ, MAP_ANON|MAP_PRIVATE, INT_MAX, 0);
234 
235 	ATF_REQUIRE(map == MAP_FAILED);
236 	ATF_REQUIRE(errno == EINVAL);
237 }
238 
239 ATF_TC_WITH_CLEANUP(mmap_loan);
240 ATF_TC_HEAD(mmap_loan, tc)
241 {
242 	atf_tc_set_md_var(tc, "descr", "Test uvm page loanout with mmap(2)");
243 }
244 
245 ATF_TC_BODY(mmap_loan, tc)
246 {
247 	char buf[BUFSIZE];
248 	char *vp, *vp2;
249 	int fd;
250 
251 	fd = open(path, O_RDWR | O_CREAT, 0600);
252 	ATF_REQUIRE(fd >= 0);
253 
254 	(void)memset(buf, 'x', sizeof(buf));
255 	(void)write(fd, buf, sizeof(buf));
256 
257 	vp = mmap(NULL, BUFSIZE, PROT_READ | PROT_WRITE,
258 	    MAP_FILE | MAP_PRIVATE, fd, 0);
259 
260 	ATF_REQUIRE(vp != MAP_FAILED);
261 
262 	vp2 = vp;
263 
264 	testloan(vp, vp2, 'A', 0);
265 	testloan(vp, vp2, 'B', 1);
266 
267 	ATF_REQUIRE(munmap(vp, BUFSIZE) == 0);
268 
269 	vp = mmap(NULL, BUFSIZE, PROT_READ | PROT_WRITE,
270 	    MAP_FILE | MAP_SHARED, fd, 0);
271 
272 	vp2 = mmap(NULL, BUFSIZE, PROT_READ | PROT_WRITE,
273 	    MAP_FILE | MAP_SHARED, fd, 0);
274 
275 	ATF_REQUIRE(vp != MAP_FAILED);
276 	ATF_REQUIRE(vp2 != MAP_FAILED);
277 
278 	testloan(vp, vp2, 'E', 1);
279 
280 	ATF_REQUIRE(munmap(vp, BUFSIZE) == 0);
281 	ATF_REQUIRE(munmap(vp2, BUFSIZE) == 0);
282 }
283 
284 ATF_TC_CLEANUP(mmap_loan, tc)
285 {
286 	(void)unlink(path);
287 }
288 
289 ATF_TC_WITH_CLEANUP(mmap_prot_1);
290 ATF_TC_HEAD(mmap_prot_1, tc)
291 {
292 	atf_tc_set_md_var(tc, "descr", "Test mmap(2) protections, #1");
293 }
294 
295 ATF_TC_BODY(mmap_prot_1, tc)
296 {
297 	void *map;
298 	int fd;
299 
300 	/*
301 	 * Open a file write-only and try to
302 	 * map it read-only. This should fail.
303 	 */
304 	fd = open(path, O_WRONLY | O_CREAT, 0700);
305 
306 	if (fd < 0)
307 		return;
308 
309 	ATF_REQUIRE(write(fd, "XXX", 3) == 3);
310 
311 	map = mmap(NULL, 3, PROT_READ, MAP_FILE|MAP_PRIVATE, fd, 0);
312 	map_check(map, 1);
313 
314 	map = mmap(NULL, 3, PROT_WRITE, MAP_FILE|MAP_PRIVATE, fd, 0);
315 	map_check(map, 0);
316 
317 	ATF_REQUIRE(close(fd) == 0);
318 }
319 
320 ATF_TC_CLEANUP(mmap_prot_1, tc)
321 {
322 	(void)unlink(path);
323 }
324 
325 ATF_TC(mmap_prot_2);
326 ATF_TC_HEAD(mmap_prot_2, tc)
327 {
328 	atf_tc_set_md_var(tc, "descr", "Test mmap(2) protections, #2");
329 }
330 
331 ATF_TC_BODY(mmap_prot_2, tc)
332 {
333 	char buf[2];
334 	void *map;
335 	pid_t pid;
336 	int sta;
337 
338 	/*
339 	 * Make a PROT_NONE mapping and try to access it.
340 	 * If we catch a SIGSEGV, all works as expected.
341 	 */
342 	map = mmap(NULL, page, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
343 	ATF_REQUIRE(map != MAP_FAILED);
344 
345 	pid = fork();
346 	ATF_REQUIRE(pid >= 0);
347 
348 	if (pid == 0) {
349 		ATF_REQUIRE(signal(SIGSEGV, map_sighandler) != SIG_ERR);
350 		ATF_REQUIRE(strlcpy(buf, map, sizeof(buf)) != 0);
351 	}
352 
353 	(void)wait(&sta);
354 
355 	ATF_REQUIRE(WIFEXITED(sta) != 0);
356 	ATF_REQUIRE(WEXITSTATUS(sta) == SIGSEGV);
357 	ATF_REQUIRE(munmap(map, page) == 0);
358 }
359 
360 ATF_TC_WITH_CLEANUP(mmap_prot_3);
361 ATF_TC_HEAD(mmap_prot_3, tc)
362 {
363 	atf_tc_set_md_var(tc, "descr", "Test mmap(2) protections, #3");
364 }
365 
366 ATF_TC_BODY(mmap_prot_3, tc)
367 {
368 	char buf[2];
369 	int fd, sta;
370 	void *map;
371 	pid_t pid;
372 
373 	/*
374 	 * Open a file, change the permissions
375 	 * to read-only, and try to map it as
376 	 * PROT_NONE. This should succeed, but
377 	 * the access should generate SIGSEGV.
378 	 */
379 	fd = open(path, O_RDWR | O_CREAT, 0700);
380 
381 	if (fd < 0)
382 #ifdef	__FreeBSD__
383 		atf_tc_skip("opening %s failed; skipping testcase: %s",
384 		    path, strerror(errno));
385 #else
386 		return;
387 #endif
388 
389 	ATF_REQUIRE(write(fd, "XXX", 3) == 3);
390 	ATF_REQUIRE(close(fd) == 0);
391 	ATF_REQUIRE(chmod(path, 0444) == 0);
392 
393 	fd = open(path, O_RDONLY);
394 	ATF_REQUIRE(fd != -1);
395 
396 	map = mmap(NULL, 3, PROT_NONE, MAP_FILE | MAP_SHARED, fd, 0);
397 	ATF_REQUIRE(map != MAP_FAILED);
398 
399 	pid = fork();
400 
401 	ATF_REQUIRE(pid >= 0);
402 
403 	if (pid == 0) {
404 		ATF_REQUIRE(signal(SIGSEGV, map_sighandler) != SIG_ERR);
405 		ATF_REQUIRE(strlcpy(buf, map, sizeof(buf)) != 0);
406 	}
407 
408 	(void)wait(&sta);
409 
410 	ATF_REQUIRE(WIFEXITED(sta) != 0);
411 	ATF_REQUIRE(WEXITSTATUS(sta) == SIGSEGV);
412 	ATF_REQUIRE(munmap(map, 3) == 0);
413 #ifdef	__FreeBSD__
414 	(void)close(fd);
415 #endif
416 }
417 
418 ATF_TC_CLEANUP(mmap_prot_3, tc)
419 {
420 	(void)unlink(path);
421 }
422 
423 ATF_TC_WITH_CLEANUP(mmap_truncate);
424 ATF_TC_HEAD(mmap_truncate, tc)
425 {
426 	atf_tc_set_md_var(tc, "descr", "Test mmap(2) and ftruncate(2)");
427 }
428 
429 ATF_TC_BODY(mmap_truncate, tc)
430 {
431 	char *map;
432 	long i;
433 	int fd;
434 
435 	fd = open(path, O_RDWR | O_CREAT, 0700);
436 
437 	if (fd < 0)
438 		return;
439 
440 	/*
441 	 * See that ftruncate(2) works
442 	 * while the file is mapped.
443 	 */
444 	ATF_REQUIRE(ftruncate(fd, page) == 0);
445 
446 	map = mmap(NULL, page, PROT_READ | PROT_WRITE, MAP_FILE|MAP_PRIVATE,
447 	     fd, 0);
448 	ATF_REQUIRE(map != MAP_FAILED);
449 
450 	for (i = 0; i < page; i++)
451 		map[i] = 'x';
452 
453 	ATF_REQUIRE(ftruncate(fd, 0) == 0);
454 	ATF_REQUIRE(ftruncate(fd, page / 8) == 0);
455 	ATF_REQUIRE(ftruncate(fd, page / 4) == 0);
456 	ATF_REQUIRE(ftruncate(fd, page / 2) == 0);
457 	ATF_REQUIRE(ftruncate(fd, page / 12) == 0);
458 	ATF_REQUIRE(ftruncate(fd, page / 64) == 0);
459 
460 	(void)munmap(map, page);
461 	ATF_REQUIRE(close(fd) == 0);
462 }
463 
464 ATF_TC_CLEANUP(mmap_truncate, tc)
465 {
466 	(void)unlink(path);
467 }
468 
469 ATF_TC_WITH_CLEANUP(mmap_truncate_signal);
470 ATF_TC_HEAD(mmap_truncate_signal, tc)
471 {
472 	atf_tc_set_md_var(tc, "descr",
473 	    "Test mmap(2) ftruncate(2) causing signal");
474 }
475 
476 ATF_TC_BODY(mmap_truncate_signal, tc)
477 {
478 	char *map;
479 	long i;
480 	int fd, sta;
481 	pid_t pid;
482 
483 	fd = open(path, O_RDWR | O_CREAT, 0700);
484 
485 	if (fd < 0)
486 		return;
487 
488 	ATF_REQUIRE(write(fd, "foo\n", 5) == 5);
489 
490 	map = mmap(NULL, page, PROT_READ, MAP_FILE|MAP_PRIVATE, fd, 0);
491 	ATF_REQUIRE(map != MAP_FAILED);
492 
493 	sta = 0;
494 	for (i = 0; i < 5; i++)
495 		sta += map[i];
496 	ATF_REQUIRE(sta == 334);
497 
498 	ATF_REQUIRE(ftruncate(fd, 0) == 0);
499 	pid = fork();
500 	ATF_REQUIRE(pid >= 0);
501 
502 	if (pid == 0) {
503 		ATF_REQUIRE(signal(SIGBUS, map_sighandler) != SIG_ERR);
504 		ATF_REQUIRE(signal(SIGSEGV, map_sighandler) != SIG_ERR);
505 		sta = 0;
506 		for (i = 0; i < page; i++)
507 			sta += map[i];
508 		/* child never will get this far, but the compiler will
509 		   not know, so better use the values calculated to
510 		   prevent the access to be optimized out */
511 		ATF_REQUIRE(i == 0);
512 		ATF_REQUIRE(sta == 0);
513 		(void)munmap(map, page);
514 		(void)close(fd);
515 		return;
516 	}
517 
518 	(void)wait(&sta);
519 
520 	ATF_REQUIRE(WIFEXITED(sta) != 0);
521 	if (WEXITSTATUS(sta) == SIGSEGV)
522 		atf_tc_fail("child process got SIGSEGV instead of SIGBUS");
523 	ATF_REQUIRE(WEXITSTATUS(sta) == SIGBUS);
524 	ATF_REQUIRE(munmap(map, page) == 0);
525 	ATF_REQUIRE(close(fd) == 0);
526 }
527 
528 ATF_TC_CLEANUP(mmap_truncate_signal, tc)
529 {
530 	(void)unlink(path);
531 }
532 
533 ATF_TC(mmap_va0);
534 ATF_TC_HEAD(mmap_va0, tc)
535 {
536 	atf_tc_set_md_var(tc, "descr", "Test mmap(2) and vm.user_va0_disable");
537 }
538 
539 ATF_TC_BODY(mmap_va0, tc)
540 {
541 	int flags = MAP_ANON | MAP_FIXED | MAP_PRIVATE;
542 	size_t len = sizeof(int);
543 	void *map;
544 	int val;
545 
546 	/*
547 	 * Make an anonymous fixed mapping at zero address. If the address
548 	 * is restricted as noted in security(7), the syscall should fail.
549 	 */
550 #ifdef __FreeBSD__
551 	if (sysctlbyname("security.bsd.map_at_zero", &val, &len, NULL, 0) != 0)
552 		atf_tc_fail("failed to read security.bsd.map_at_zero");
553 	val = !val; /* 1 == enable  map at zero */
554 #endif
555 #ifdef __NetBSD__
556 	if (sysctlbyname("vm.user_va0_disable", &val, &len, NULL, 0) != 0)
557 		atf_tc_fail("failed to read vm.user_va0_disable");
558 #endif
559 
560 	map = mmap(NULL, page, PROT_EXEC, flags, -1, 0);
561 	map_check(map, val);
562 
563 	map = mmap(NULL, page, PROT_READ, flags, -1, 0);
564 	map_check(map, val);
565 
566 	map = mmap(NULL, page, PROT_WRITE, flags, -1, 0);
567 	map_check(map, val);
568 
569 	map = mmap(NULL, page, PROT_READ|PROT_WRITE, flags, -1, 0);
570 	map_check(map, val);
571 
572 	map = mmap(NULL, page, PROT_EXEC|PROT_READ|PROT_WRITE, flags, -1, 0);
573 	map_check(map, val);
574 }
575 
576 ATF_TP_ADD_TCS(tp)
577 {
578 	page = sysconf(_SC_PAGESIZE);
579 	ATF_REQUIRE(page >= 0);
580 
581 #ifdef __NetBSD__
582 	ATF_TP_ADD_TC(tp, mmap_block);
583 #endif
584 	ATF_TP_ADD_TC(tp, mmap_err);
585 	ATF_TP_ADD_TC(tp, mmap_loan);
586 	ATF_TP_ADD_TC(tp, mmap_prot_1);
587 	ATF_TP_ADD_TC(tp, mmap_prot_2);
588 	ATF_TP_ADD_TC(tp, mmap_prot_3);
589 	ATF_TP_ADD_TC(tp, mmap_truncate);
590 	ATF_TP_ADD_TC(tp, mmap_truncate_signal);
591 	ATF_TP_ADD_TC(tp, mmap_va0);
592 
593 	return atf_no_error();
594 }
595