xref: /minix/tests/lib/libc/sys/t_mlock.c (revision ebfedea0)
1 /* $NetBSD: t_mlock.c,v 1.4 2012/09/08 12:25:05 martin 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 1.4 2012/09/08 12:25:05 martin Exp $");
33 
34 #include <sys/mman.h>
35 #include <sys/resource.h>
36 #include <sys/wait.h>
37 #define _KMEMUSER
38 #include <machine/vmparam.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 <unistd.h>
46 
47 static long page = 0;
48 
49 ATF_TC(mlock_clip);
50 ATF_TC_HEAD(mlock_clip, tc)
51 {
52 	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
53 	    "clips if the clip address is within the entry (PR kern/44788)");
54 }
55 
56 ATF_TC_BODY(mlock_clip, tc)
57 {
58 	void *buf;
59 
60 	buf = malloc(page);
61 	ATF_REQUIRE(buf != NULL);
62 
63 	if (page < 1024)
64 		atf_tc_skip("page size too small");
65 
66 	for (size_t i = page; i >= 1; i = i - 1024) {
67 		(void)mlock(buf, page - i);
68 		(void)munlock(buf, page - i);
69 	}
70 
71 	free(buf);
72 }
73 
74 ATF_TC(mlock_err);
75 ATF_TC_HEAD(mlock_err, tc)
76 {
77 	atf_tc_set_md_var(tc, "descr",
78 	    "Test error conditions in mlock(2) and munlock(2)");
79 }
80 
81 ATF_TC_BODY(mlock_err, tc)
82 {
83 	void *invalid_ptr;
84 	int null_errno = ENOMEM;	/* error expected for NULL */
85 
86 #ifdef VM_MIN_ADDRESS
87 	if ((uintptr_t)VM_MIN_ADDRESS > 0)
88 		null_errno = EINVAL;	/* NULL is not inside user VM */
89 #endif
90 
91 	errno = 0;
92 	ATF_REQUIRE_ERRNO(null_errno, mlock(NULL, page) == -1);
93 
94 	errno = 0;
95 	ATF_REQUIRE_ERRNO(null_errno, mlock((char *)0, page) == -1);
96 
97 	errno = 0;
98 	ATF_REQUIRE_ERRNO(EINVAL, mlock((char *)-1, page) == -1);
99 
100 	errno = 0;
101 	ATF_REQUIRE_ERRNO(null_errno, munlock(NULL, page) == -1);
102 
103 	errno = 0;
104 	ATF_REQUIRE_ERRNO(null_errno, munlock((char *)0, page) == -1);
105 
106 	errno = 0;
107 	ATF_REQUIRE_ERRNO(EINVAL, munlock((char *)-1, page) == -1);
108 
109 	/*
110 	 * Try to create a pointer to an unmapped page - first after current
111 	 * brk will likely do.
112 	 */
113 	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
114 	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
115 
116 	errno = 0;
117 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
118 
119 	errno = 0;
120 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
121 }
122 
123 ATF_TC(mlock_limits);
124 ATF_TC_HEAD(mlock_limits, tc)
125 {
126 	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
127 }
128 
129 ATF_TC_BODY(mlock_limits, tc)
130 {
131 	struct rlimit res;
132 	void *buf;
133 	pid_t pid;
134 	int sta;
135 
136 	buf = malloc(page);
137 	ATF_REQUIRE(buf != NULL);
138 
139 	pid = fork();
140 	ATF_REQUIRE(pid >= 0);
141 
142 	if (pid == 0) {
143 
144 		for (ssize_t i = page; i >= 2; i -= 100) {
145 
146 			res.rlim_cur = i - 1;
147 			res.rlim_max = i - 1;
148 
149 			(void)fprintf(stderr, "trying to lock %zd bytes "
150 			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
151 
152 			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
153 				_exit(EXIT_FAILURE);
154 
155 			errno = 0;
156 
157 			if (mlock(buf, i) != -1 || errno != EAGAIN) {
158 				(void)munlock(buf, i);
159 				_exit(EXIT_FAILURE);
160 			}
161 		}
162 
163 		_exit(EXIT_SUCCESS);
164 	}
165 
166 	(void)wait(&sta);
167 
168 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
169 		atf_tc_fail("mlock(2) locked beyond system limits");
170 
171 	free(buf);
172 }
173 
174 ATF_TC(mlock_mmap);
175 ATF_TC_HEAD(mlock_mmap, tc)
176 {
177 	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
178 }
179 
180 ATF_TC_BODY(mlock_mmap, tc)
181 {
182 	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
183 	void *buf;
184 
185 	/*
186 	 * Make a wired RW mapping and check that mlock(2)
187 	 * does not fail for the (already locked) mapping.
188 	 */
189 	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
190 
191 	ATF_REQUIRE(buf != MAP_FAILED);
192 	ATF_REQUIRE(mlock(buf, page) == 0);
193 	ATF_REQUIRE(munlock(buf, page) == 0);
194 	ATF_REQUIRE(munmap(buf, page) == 0);
195 	ATF_REQUIRE(munlock(buf, page) != 0);
196 
197 	/*
198 	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
199 	 */
200 	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
201 
202 	ATF_REQUIRE(buf != MAP_FAILED);
203 	ATF_REQUIRE(mlock(buf, page) != 0);
204 	ATF_REQUIRE(munmap(buf, page) == 0);
205 }
206 
207 ATF_TC(mlock_nested);
208 ATF_TC_HEAD(mlock_nested, tc)
209 {
210 	atf_tc_set_md_var(tc, "descr",
211 	    "Test that consecutive mlock(2) calls succeed");
212 }
213 
214 ATF_TC_BODY(mlock_nested, tc)
215 {
216 	const size_t maxiter = 100;
217 	void *buf;
218 
219 	buf = malloc(page);
220 	ATF_REQUIRE(buf != NULL);
221 
222 	for (size_t i = 0; i < maxiter; i++)
223 		ATF_REQUIRE(mlock(buf, page) == 0);
224 
225 	ATF_REQUIRE(munlock(buf, page) == 0);
226 	free(buf);
227 }
228 
229 ATF_TP_ADD_TCS(tp)
230 {
231 
232 	page = sysconf(_SC_PAGESIZE);
233 	ATF_REQUIRE(page >= 0);
234 
235 	ATF_TP_ADD_TC(tp, mlock_clip);
236 	ATF_TP_ADD_TC(tp, mlock_err);
237 	ATF_TP_ADD_TC(tp, mlock_limits);
238 	ATF_TP_ADD_TC(tp, mlock_mmap);
239 	ATF_TP_ADD_TC(tp, mlock_nested);
240 
241 	return atf_no_error();
242 }
243