xref: /netbsd-src/tests/lib/libc/sys/t_mlock.c (revision deb6f0161a9109e7de9b519dc8dfb9478668dcdd)
1 /* $NetBSD: t_mlock.c,v 1.6 2016/08/09 12:02:44 kre Exp $ */
2 
3 /*-
4  * Copyright (c) 2012 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 #include <sys/cdefs.h>
32 __RCSID("$NetBSD: t_mlock.c,v 1.6 2016/08/09 12:02:44 kre Exp $");
33 
34 #include <sys/mman.h>
35 #include <sys/resource.h>
36 #include <sys/sysctl.h>
37 #include <sys/wait.h>
38 
39 #include <errno.h>
40 #include <atf-c.h>
41 #include <stdint.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <unistd.h>
45 
46 static long page = 0;
47 
48 ATF_TC(mlock_clip);
49 ATF_TC_HEAD(mlock_clip, tc)
50 {
51 	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
52 	    "clips if the clip address is within the entry (PR kern/44788)");
53 }
54 
55 ATF_TC_BODY(mlock_clip, tc)
56 {
57 	void *buf;
58 
59 	buf = malloc(page);
60 	ATF_REQUIRE(buf != NULL);
61 
62 	if (page < 1024)
63 		atf_tc_skip("page size too small");
64 
65 	for (size_t i = page; i >= 1; i = i - 1024) {
66 		(void)mlock(buf, page - i);
67 		(void)munlock(buf, page - i);
68 	}
69 
70 	free(buf);
71 }
72 
73 ATF_TC(mlock_err);
74 ATF_TC_HEAD(mlock_err, tc)
75 {
76 	atf_tc_set_md_var(tc, "descr",
77 	    "Test error conditions in mlock(2) and munlock(2)");
78 }
79 
80 ATF_TC_BODY(mlock_err, tc)
81 {
82 	void *invalid_ptr;
83 	void *buf;
84 
85 	/*
86 	 * Any bad address must return ENOMEM (for lock & unlock)
87 	 */
88 	errno = 0;
89 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
90 
91 	errno = 0;
92 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
93 
94 	errno = 0;
95 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
96 
97 	errno = 0;
98 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
99 
100 	errno = 0;
101 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
102 
103 	errno = 0;
104 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
105 
106 	buf = malloc(page);
107 	ATF_REQUIRE(buf != NULL);
108 
109 	/*
110 	 * unlocking memory that is not locked is an error...
111 	 */
112 
113 	errno = 0;
114 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
115 
116 	/*
117 	 * These are permitted to fail (EINVAL) but do not on NetBSD
118 	 */
119 	ATF_REQUIRE(mlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
120 	ATF_REQUIRE(munlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
121 
122 	(void)free(buf);
123 
124 	/*
125 	 * Try to create a pointer to an unmapped page - first after current
126 	 * brk will likely do.
127 	 */
128 	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
129 	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
130 
131 	errno = 0;
132 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
133 
134 	errno = 0;
135 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
136 }
137 
138 ATF_TC(mlock_limits);
139 ATF_TC_HEAD(mlock_limits, tc)
140 {
141 	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
142 }
143 
144 ATF_TC_BODY(mlock_limits, tc)
145 {
146 	struct rlimit res;
147 	void *buf;
148 	pid_t pid;
149 	int sta;
150 
151 	buf = malloc(page);
152 	ATF_REQUIRE(buf != NULL);
153 
154 	pid = fork();
155 	ATF_REQUIRE(pid >= 0);
156 
157 	if (pid == 0) {
158 
159 		for (ssize_t i = page; i >= 2; i -= 100) {
160 
161 			res.rlim_cur = i - 1;
162 			res.rlim_max = i - 1;
163 
164 			(void)fprintf(stderr, "trying to lock %zd bytes "
165 			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
166 
167 			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
168 				_exit(EXIT_FAILURE);
169 
170 			errno = 0;
171 
172 			if (mlock(buf, i) != -1 || errno != EAGAIN) {
173 				(void)munlock(buf, i);
174 				_exit(EXIT_FAILURE);
175 			}
176 		}
177 
178 		_exit(EXIT_SUCCESS);
179 	}
180 
181 	(void)wait(&sta);
182 
183 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
184 		atf_tc_fail("mlock(2) locked beyond system limits");
185 
186 	free(buf);
187 }
188 
189 ATF_TC(mlock_mmap);
190 ATF_TC_HEAD(mlock_mmap, tc)
191 {
192 	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
193 }
194 
195 ATF_TC_BODY(mlock_mmap, tc)
196 {
197 	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
198 	void *buf;
199 
200 	/*
201 	 * Make a wired RW mapping and check that mlock(2)
202 	 * does not fail for the (already locked) mapping.
203 	 */
204 	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
205 
206 	ATF_REQUIRE(buf != MAP_FAILED);
207 	ATF_REQUIRE(mlock(buf, page) == 0);
208 	ATF_REQUIRE(munlock(buf, page) == 0);
209 	ATF_REQUIRE(munmap(buf, page) == 0);
210 	ATF_REQUIRE(munlock(buf, page) != 0);
211 
212 	/*
213 	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
214 	 */
215 	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
216 
217 	ATF_REQUIRE(buf != MAP_FAILED);
218 	ATF_REQUIRE(mlock(buf, page) != 0);
219 	ATF_REQUIRE(munmap(buf, page) == 0);
220 }
221 
222 ATF_TC(mlock_nested);
223 ATF_TC_HEAD(mlock_nested, tc)
224 {
225 	atf_tc_set_md_var(tc, "descr",
226 	    "Test that consecutive mlock(2) calls succeed");
227 }
228 
229 ATF_TC_BODY(mlock_nested, tc)
230 {
231 	const size_t maxiter = 100;
232 	void *buf;
233 
234 	buf = malloc(page);
235 	ATF_REQUIRE(buf != NULL);
236 
237 	for (size_t i = 0; i < maxiter; i++)
238 		ATF_REQUIRE(mlock(buf, page) == 0);
239 
240 	ATF_REQUIRE(munlock(buf, page) == 0);
241 	free(buf);
242 }
243 
244 ATF_TP_ADD_TCS(tp)
245 {
246 
247 	page = sysconf(_SC_PAGESIZE);
248 	ATF_REQUIRE(page >= 0);
249 
250 	ATF_TP_ADD_TC(tp, mlock_clip);
251 	ATF_TP_ADD_TC(tp, mlock_err);
252 	ATF_TP_ADD_TC(tp, mlock_limits);
253 	ATF_TP_ADD_TC(tp, mlock_mmap);
254 	ATF_TP_ADD_TC(tp, mlock_nested);
255 
256 	return atf_no_error();
257 }
258