xref: /openbsd/regress/lib/libc/sys/t_mlock.c (revision 5a38ef86)
1 /*	$OpenBSD: t_mlock.c,v 1.3 2021/12/13 16:56:48 deraadt Exp $	*/
2 /* $NetBSD: t_mlock.c,v 1.8 2020/01/24 08:45:16 skrll Exp $ */
3 
4 /*-
5  * Copyright (c) 2012 The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Jukka Ruohonen.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #include "macros.h"
34 
35 #include <sys/mman.h>
36 #include <sys/resource.h>
37 #include <sys/sysctl.h>
38 #include <sys/wait.h>
39 
40 #include <errno.h>
41 #include "atf-c.h"
42 #include <stdint.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 static long page = 0;
49 
50 ATF_TC(mlock_clip);
51 ATF_TC_HEAD(mlock_clip, tc)
52 {
53 	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
54 	    "clips if the clip address is within the entry (PR kern/44788)");
55 }
56 
57 ATF_TC_BODY(mlock_clip, tc)
58 {
59 	void *buf;
60 	int err1, err2;
61 
62 	buf = malloc(page);
63 	ATF_REQUIRE(buf != NULL);
64 	fprintf(stderr, "mlock_clip: buf = %p (page=%ld)\n", buf, page);
65 
66 	if (page < 1024)
67 		atf_tc_skip("page size too small");
68 
69 	for (size_t i = page; i >= 1; i = i - 1024) {
70 		err1 = mlock(buf, page - i);
71 		if (err1 != 0)
72 			fprintf(stderr, "mlock_clip: page=%ld i=%zu,"
73 			    " mlock(%p, %ld): %s\n", page, i, buf, page - i,
74 			    strerror(errno));
75 		err2 = munlock(buf, page - i);
76 		if (err2 != 0)
77 			fprintf(stderr, "mlock_clip: page=%ld i=%zu,"
78 			    " munlock(%p, %ld): %s (mlock %s)\n", page, i,
79 			    buf, page - i, strerror(errno), err1?"failed":"ok");
80 	}
81 
82 	free(buf);
83 }
84 
85 ATF_TC(mlock_err);
86 ATF_TC_HEAD(mlock_err, tc)
87 {
88 	atf_tc_set_md_var(tc, "descr",
89 	    "Test error conditions in mlock(2) and munlock(2)");
90 }
91 
92 ATF_TC_BODY(mlock_err, tc)
93 {
94 	void *invalid_ptr;
95 	void *buf;
96 	int mlock_err, munlock_err;
97 
98 	/*
99 	 * Any bad address must return ENOMEM (for lock & unlock)
100 	 */
101 	errno = 0;
102 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
103 
104 	errno = 0;
105 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
106 
107 	errno = 0;
108 #ifdef __OpenBSD__
109 	ATF_REQUIRE_ERRNO(EINVAL, mlock((char *)-1, page) == -1);
110 #else
111 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
112 #endif
113 
114 	errno = 0;
115 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
116 
117 	errno = 0;
118 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
119 
120 	errno = 0;
121 #ifdef __OpenBSD__
122 	ATF_REQUIRE_ERRNO(EINVAL, munlock((char *)-1, page) == -1);
123 #else
124 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
125 #endif
126 
127 	buf = malloc(page);
128 	ATF_REQUIRE(buf != NULL);
129 	fprintf(stderr, "mlock_err: buf = %p (page=%ld)\n", buf, page);
130 
131 	/*
132 	 * unlocking memory that is not locked is an error...
133 	 */
134 
135 #ifndef __OpenBSD__
136 	errno = 0;
137 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
138 #endif
139 
140 	/*
141 	 * These are permitted to fail (EINVAL) but do not on NetBSD
142 	 */
143 	mlock_err = mlock((void *)(((uintptr_t)buf) + page/3), page/5);
144 	if (mlock_err != 0)
145 	    fprintf(stderr, "mlock_err: mlock(%p, %ld): %d [%d] %s\n",
146 		(void *)(((uintptr_t)buf) + page/3), page/5, mlock_err,
147 		errno, strerror(errno));
148 	ATF_REQUIRE(mlock_err == 0);
149 	munlock_err= munlock((void *)(((uintptr_t)buf) + page/3), page/5);
150 	if (munlock_err != 0)
151 	    fprintf(stderr, "mlock_err: munlock(%p, %ld): %d [%d] %s\n",
152 		(void *)(((uintptr_t)buf) + page/3), page/5, munlock_err,
153 		errno, strerror(errno));
154 	ATF_REQUIRE(munlock_err == 0);
155 
156 	(void)free(buf);
157 
158 	/*
159 	 * Try to create a pointer to an unmapped page - first after current
160 	 * brk will likely do.
161 	 */
162 	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
163 	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
164 
165 	errno = 0;
166 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
167 
168 	errno = 0;
169 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
170 }
171 
172 ATF_TC(mlock_limits);
173 ATF_TC_HEAD(mlock_limits, tc)
174 {
175 	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
176 }
177 
178 ATF_TC_BODY(mlock_limits, tc)
179 {
180 	struct rlimit res;
181 	void *buf;
182 	pid_t pid;
183 	int sta;
184 
185 	buf = malloc(page);
186 	ATF_REQUIRE(buf != NULL);
187 	fprintf(stderr, "mlock_limits: buf = %p (page=%ld)\n", buf, page);
188 
189 	pid = fork();
190 	ATF_REQUIRE(pid >= 0);
191 
192 	if (pid == 0) {
193 
194 		for (ssize_t i = page; i >= 2; i -= 100) {
195 
196 			res.rlim_cur = i - 1;
197 			res.rlim_max = i - 1;
198 
199 			(void)fprintf(stderr, "trying to lock %zu bytes "
200 			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
201 
202 			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
203 				_exit(EXIT_FAILURE);
204 
205 			errno = 0;
206 
207 			if ((sta = mlock(buf, i)) != -1 || errno != EAGAIN) {
208 				fprintf(stderr, "mlock(%p, %zu): %d [%d] %s\n",
209 				    buf, i, sta, errno, strerror(errno));
210 				(void)munlock(buf, i);
211 				_exit(EXIT_FAILURE);
212 			}
213 		}
214 
215 		_exit(EXIT_SUCCESS);
216 	}
217 
218 	(void)wait(&sta);
219 
220 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
221 		atf_tc_fail("mlock(2) locked beyond system limits");
222 
223 	free(buf);
224 }
225 
226 ATF_TC(mlock_mmap);
227 ATF_TC_HEAD(mlock_mmap, tc)
228 {
229 	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
230 }
231 
232 ATF_TC_BODY(mlock_mmap, tc)
233 {
234 #ifdef __OpenBSD__
235 	static const int flags = MAP_ANON | MAP_PRIVATE;
236 #else
237 	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
238 #endif
239 	void *buf;
240 
241 	/*
242 	 * Make a wired RW mapping and check that mlock(2)
243 	 * does not fail for the (already locked) mapping.
244 	 */
245 	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
246 
247 	if (buf == MAP_FAILED)
248 		fprintf(stderr,
249 		    "mlock_mmap: mmap(NULL, %ld, %#x, %#x, -1, 0): MAP_FAILED"
250 		    " [%d] %s\n", page, PROT_READ | PROT_WRITE, flags, errno,
251 		    strerror(errno));
252 
253 	ATF_REQUIRE(buf != MAP_FAILED);
254 
255 	fprintf(stderr, "mlock_mmap: buf=%p, page=%ld\n", buf, page);
256 
257 	ATF_REQUIRE(mlock(buf, page) == 0);
258 	ATF_REQUIRE(munlock(buf, page) == 0);
259 	ATF_REQUIRE(munmap(buf, page) == 0);
260 	ATF_REQUIRE(munlock(buf, page) != 0);
261 
262 	fprintf(stderr, "mlock_mmap: first test succeeded\n");
263 
264 	/*
265 	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
266 	 */
267 	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
268 
269 	if (buf == MAP_FAILED)
270 		fprintf(stderr,
271 		    "mlock_mmap: mmap(NULL, %ld, %#x, %#x, -1, 0): MAP_FAILED"
272 		    " [%d] %s\n", page, PROT_NONE, flags, errno,
273 		    strerror(errno));
274 
275 	ATF_REQUIRE(buf != MAP_FAILED);
276 	ATF_REQUIRE(mlock(buf, page) != 0);
277 	ATF_REQUIRE(munmap(buf, page) == 0);
278 
279 	fprintf(stderr, "mlock_mmap: second test succeeded\n");
280 }
281 
282 ATF_TC(mlock_nested);
283 ATF_TC_HEAD(mlock_nested, tc)
284 {
285 	atf_tc_set_md_var(tc, "descr",
286 	    "Test that consecutive mlock(2) calls succeed");
287 }
288 
289 ATF_TC_BODY(mlock_nested, tc)
290 {
291 	const size_t maxiter = 100;
292 	void *buf;
293 	int err;
294 
295 	buf = malloc(page);
296 	ATF_REQUIRE(buf != NULL);
297 	fprintf(stderr, "mlock_nested: buf = %p (page=%ld)\n", buf, page);
298 
299 	for (size_t i = 0; i < maxiter; i++) {
300 		err = mlock(buf, page);
301 		if (err != 0)
302 		    fprintf(stderr,
303 		    "mlock_nested: i=%zu (of %zu) mlock(%p, %ld): %d [%d] %s\n",
304 			i, maxiter, buf, page, err, errno, strerror(errno));
305 		ATF_REQUIRE(err == 0);
306 	}
307 
308 	err = munlock(buf, page);
309 	if (err != 0)
310 		fprintf(stderr, "mlock_nested: munlock(%p, %ld): %d [%d] %s\n",
311 		    buf, page, err, errno, strerror(errno));
312 	ATF_REQUIRE(err == 0);
313 	free(buf);
314 }
315 
316 ATF_TP_ADD_TCS(tp)
317 {
318 
319 	page = sysconf(_SC_PAGESIZE);
320 	ATF_REQUIRE(page >= 0);
321 
322 	ATF_TP_ADD_TC(tp, mlock_clip);
323 	ATF_TP_ADD_TC(tp, mlock_err);
324 	ATF_TP_ADD_TC(tp, mlock_limits);
325 	ATF_TP_ADD_TC(tp, mlock_mmap);
326 	ATF_TP_ADD_TC(tp, mlock_nested);
327 
328 	return atf_no_error();
329 }
330