xref: /netbsd-src/tests/lib/libc/sys/t_mlock.c (revision 062cd249892f31a10349de47b78d800cd8ae2c25)
1 /* $NetBSD: t_mlock.c,v 1.2 2012/04/21 01:15:13 jruoho 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 1.2 2012/04/21 01:15:13 jruoho Exp $");
33 
34 #include <sys/mman.h>
35 #include <sys/resource.h>
36 #include <sys/wait.h>
37 
38 #include <errno.h>
39 #include <atf-c.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <unistd.h>
43 
44 static long page = 0;
45 
46 ATF_TC(mlock_clip);
47 ATF_TC_HEAD(mlock_clip, tc)
48 {
49 	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
50 	    "clips if the clip address is within the entry (PR kern/44788)");
51 }
52 
53 ATF_TC_BODY(mlock_clip, tc)
54 {
55 	void *buf;
56 
57 	buf = malloc(page);
58 	ATF_REQUIRE(buf != NULL);
59 
60 	if (page < 1024)
61 		atf_tc_skip("page size too small");
62 
63 	for (size_t i = page; i >= 1; i = i - 1024) {
64 		(void)mlock(buf, page - i);
65 		(void)munlock(buf, page - i);
66 	}
67 
68 	free(buf);
69 }
70 
71 ATF_TC(mlock_err);
72 ATF_TC_HEAD(mlock_err, tc)
73 {
74 	atf_tc_set_md_var(tc, "descr",
75 	    "Test error conditions in mlock(2) and munlock(2)");
76 }
77 
78 ATF_TC_BODY(mlock_err, tc)
79 {
80 
81 	errno = 0;
82 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
83 
84 	errno = 0;
85 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
86 
87 	errno = 0;
88 	ATF_REQUIRE_ERRNO(EINVAL, mlock((char *)-1, page) == -1);
89 
90 	errno = 0;
91 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
92 
93 	errno = 0;
94 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
95 
96 	errno = 0;
97 	ATF_REQUIRE_ERRNO(EINVAL, munlock((char *)-1, page) == -1);
98 }
99 
100 ATF_TC(mlock_limits);
101 ATF_TC_HEAD(mlock_limits, tc)
102 {
103 	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
104 }
105 
106 ATF_TC_BODY(mlock_limits, tc)
107 {
108 	struct rlimit res;
109 	void *buf;
110 	pid_t pid;
111 	int sta;
112 
113 	buf = malloc(page);
114 	ATF_REQUIRE(buf != NULL);
115 
116 	pid = fork();
117 	ATF_REQUIRE(pid >= 0);
118 
119 	if (pid == 0) {
120 
121 		for (ssize_t i = page; i >= 2; i -= 100) {
122 
123 			res.rlim_cur = i - 1;
124 			res.rlim_max = i - 1;
125 
126 			(void)fprintf(stderr, "trying to lock %zd bytes "
127 			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
128 
129 			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
130 				_exit(EXIT_FAILURE);
131 
132 			errno = 0;
133 
134 			if (mlock(buf, i) != -1 || errno != EAGAIN) {
135 				(void)munlock(buf, i);
136 				_exit(EXIT_FAILURE);
137 			}
138 		}
139 
140 		_exit(EXIT_SUCCESS);
141 	}
142 
143 	(void)wait(&sta);
144 
145 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
146 		atf_tc_fail("mlock(2) locked beyond system limits");
147 
148 	free(buf);
149 }
150 
151 ATF_TC(mlock_mmap);
152 ATF_TC_HEAD(mlock_mmap, tc)
153 {
154 	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
155 }
156 
157 ATF_TC_BODY(mlock_mmap, tc)
158 {
159 	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
160 	void *buf;
161 
162 	/*
163 	 * Make a wired RW mapping and check that mlock(2)
164 	 * does not fail for the (already locked) mapping.
165 	 */
166 	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
167 
168 	ATF_REQUIRE(buf != MAP_FAILED);
169 	ATF_REQUIRE(mlock(buf, page) == 0);
170 	ATF_REQUIRE(munlock(buf, page) == 0);
171 	ATF_REQUIRE(munmap(buf, page) == 0);
172 	ATF_REQUIRE(munlock(buf, page) != 0);
173 
174 	/*
175 	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
176 	 */
177 	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
178 
179 	ATF_REQUIRE(buf != MAP_FAILED);
180 	ATF_REQUIRE(mlock(buf, page) != 0);
181 	ATF_REQUIRE(munmap(buf, page) == 0);
182 }
183 
184 ATF_TC(mlock_nested);
185 ATF_TC_HEAD(mlock_nested, tc)
186 {
187 	atf_tc_set_md_var(tc, "descr",
188 	    "Test that consecutive mlock(2) calls succeed");
189 }
190 
191 ATF_TC_BODY(mlock_nested, tc)
192 {
193 	const size_t maxiter = 100;
194 	void *buf;
195 
196 	buf = malloc(page);
197 	ATF_REQUIRE(buf != NULL);
198 
199 	for (size_t i = 0; i < maxiter; i++)
200 		ATF_REQUIRE(mlock(buf, page) == 0);
201 
202 	ATF_REQUIRE(munlock(buf, page) == 0);
203 	free(buf);
204 }
205 
206 ATF_TP_ADD_TCS(tp)
207 {
208 
209 	page = sysconf(_SC_PAGESIZE);
210 	ATF_REQUIRE(page >= 0);
211 
212 	ATF_TP_ADD_TC(tp, mlock_clip);
213 	ATF_TP_ADD_TC(tp, mlock_err);
214 	ATF_TP_ADD_TC(tp, mlock_limits);
215 	ATF_TP_ADD_TC(tp, mlock_mmap);
216 	ATF_TP_ADD_TC(tp, mlock_nested);
217 
218 	return atf_no_error();
219 }
220