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 #ifdef __FreeBSD__
35 #include <sys/param.h> /* NetBSD requires sys/param.h for sysctl(3), unlike FreeBSD */
36 #endif
37 #include <sys/mman.h>
38 #include <sys/resource.h>
39 #include <sys/sysctl.h>
40 #include <sys/wait.h>
41 
42 #include <errno.h>
43 #include <atf-c.h>
44 #include <stdint.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <unistd.h>
48 
49 #ifdef __FreeBSD__
50 #include <limits.h>
51 #define _KMEMUSER
52 #include <machine/vmparam.h>
53 
54 void set_vm_max_wired(int);
55 void restore_vm_max_wired(void);
56 #endif
57 
58 static long page = 0;
59 
60 ATF_TC(mlock_clip);
61 ATF_TC_HEAD(mlock_clip, tc)
62 {
63 	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
64 	    "clips if the clip address is within the entry (PR kern/44788)");
65 }
66 
67 ATF_TC_BODY(mlock_clip, tc)
68 {
69 	void *buf;
70 
71 	buf = malloc(page);
72 	ATF_REQUIRE(buf != NULL);
73 
74 	if (page < 1024)
75 		atf_tc_skip("page size too small");
76 
77 	for (size_t i = page; i >= 1; i = i - 1024) {
78 		(void)mlock(buf, page - i);
79 		(void)munlock(buf, page - i);
80 	}
81 
82 	free(buf);
83 }
84 
85 #ifdef __FreeBSD__
86 ATF_TC_WITH_CLEANUP(mlock_err);
87 #else
88 ATF_TC(mlock_err);
89 #endif
90 ATF_TC_HEAD(mlock_err, tc)
91 {
92 	atf_tc_set_md_var(tc, "descr",
93 	    "Test error conditions in mlock(2) and munlock(2)");
94 #ifdef __FreeBSD__
95 	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
96 	atf_tc_set_md_var(tc, "require.user", "root");
97 #endif
98 }
99 
100 ATF_TC_BODY(mlock_err, tc)
101 {
102 #ifdef __NetBSD__
103 	unsigned long vmin = 0;
104 	size_t len = sizeof(vmin);
105 #endif
106 #if !defined(__aarch64__) && !defined(__riscv__)
107 	void *invalid_ptr;
108 #endif
109 	int null_errno = ENOMEM;	/* error expected for NULL */
110 	void *buf;
111 
112 #ifdef __FreeBSD__
113 #ifdef VM_MIN_ADDRESS
114 	if ((uintptr_t)VM_MIN_ADDRESS > 0)
115 		null_errno = EINVAL;	/* NULL is not inside user VM */
116 #endif
117 	/* Set max_wired really really high to avoid EAGAIN */
118 	set_vm_max_wired(INT_MAX);
119 #else
120 	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
121 		atf_tc_fail("failed to read vm.minaddress");
122 	/*
123 	 * Any bad address must return ENOMEM (for lock & unlock)
124 	 */
125 	errno = 0;
126 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
127 
128 	if (vmin > 0)
129 		null_errno = EINVAL;	/* NULL is not inside user VM */
130 #endif
131 
132 	errno = 0;
133 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
134 
135 	errno = 0;
136 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
137 
138 	errno = 0;
139 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
140 
141 	errno = 0;
142 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
143 
144 	errno = 0;
145 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
146 
147 	buf = malloc(page);
148 	ATF_REQUIRE(buf != NULL);
149 
150 	/*
151 	 * unlocking memory that is not locked is an error...
152 	 */
153 
154 	errno = 0;
155 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
156 
157 /* There is no sbrk on AArch64 and RISC-V */
158 #if !defined(__aarch64__) && !defined(__riscv__)
159 	/*
160 	 * These are permitted to fail (EINVAL) but do not on NetBSD
161 	 */
162 	ATF_REQUIRE(mlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
163 	ATF_REQUIRE(munlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
164 
165 	(void)free(buf);
166 
167 	/*
168 	 * Try to create a pointer to an unmapped page - first after current
169 	 * brk will likely do.
170 	 */
171 	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
172 	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
173 
174 	errno = 0;
175 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
176 
177 	errno = 0;
178 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
179 #endif
180 }
181 
182 #ifdef __FreeBSD__
183 ATF_TC_CLEANUP(mlock_err, tc)
184 {
185 
186 	restore_vm_max_wired();
187 }
188 #endif
189 
190 ATF_TC(mlock_limits);
191 ATF_TC_HEAD(mlock_limits, tc)
192 {
193 	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
194 }
195 
196 ATF_TC_BODY(mlock_limits, tc)
197 {
198 	struct rlimit res;
199 	void *buf;
200 	pid_t pid;
201 	int sta;
202 
203 	buf = malloc(page);
204 	ATF_REQUIRE(buf != NULL);
205 
206 	pid = fork();
207 	ATF_REQUIRE(pid >= 0);
208 
209 	if (pid == 0) {
210 
211 		for (ssize_t i = page; i >= 2; i -= 100) {
212 
213 			res.rlim_cur = i - 1;
214 			res.rlim_max = i - 1;
215 
216 			(void)fprintf(stderr, "trying to lock %zd bytes "
217 			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
218 
219 			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
220 				_exit(EXIT_FAILURE);
221 
222 			errno = 0;
223 
224 #ifdef __FreeBSD__
225 			/*
226 			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
227 			 * FreeBSD does.
228 			 *
229 			 * See: NetBSD PR # kern/48962 for more details.
230 			 */
231 			if (mlock(buf, i) != -1 || errno != ENOMEM) {
232 #else
233 			if (mlock(buf, i) != -1 || errno != EAGAIN) {
234 #endif
235 				(void)munlock(buf, i);
236 				_exit(EXIT_FAILURE);
237 			}
238 		}
239 
240 		_exit(EXIT_SUCCESS);
241 	}
242 
243 	(void)wait(&sta);
244 
245 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
246 		atf_tc_fail("mlock(2) locked beyond system limits");
247 
248 	free(buf);
249 }
250 
251 #ifdef __FreeBSD__
252 ATF_TC_WITH_CLEANUP(mlock_mmap);
253 #else
254 ATF_TC(mlock_mmap);
255 #endif
256 ATF_TC_HEAD(mlock_mmap, tc)
257 {
258 	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
259 #ifdef __FreeBSD__
260 	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
261 	atf_tc_set_md_var(tc, "require.user", "root");
262 #endif
263 }
264 
265 ATF_TC_BODY(mlock_mmap, tc)
266 {
267 #ifdef __NetBSD__
268 	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
269 #else
270 	static const int flags = MAP_ANON | MAP_PRIVATE;
271 #endif
272 	void *buf;
273 
274 #ifdef __FreeBSD__
275 	/* Set max_wired really really high to avoid EAGAIN */
276 	set_vm_max_wired(INT_MAX);
277 #endif
278 
279 	/*
280 	 * Make a wired RW mapping and check that mlock(2)
281 	 * does not fail for the (already locked) mapping.
282 	 */
283 	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
284 
285 	ATF_REQUIRE(buf != MAP_FAILED);
286 #ifdef __FreeBSD__
287 	/*
288 	 * The duplicate mlock call is added to ensure that the call works
289 	 * as described above without MAP_WIRED support.
290 	 */
291 	ATF_REQUIRE(mlock(buf, page) == 0);
292 #endif
293 	ATF_REQUIRE(mlock(buf, page) == 0);
294 	ATF_REQUIRE(munlock(buf, page) == 0);
295 	ATF_REQUIRE(munmap(buf, page) == 0);
296 	ATF_REQUIRE(munlock(buf, page) != 0);
297 
298 	/*
299 	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
300 	 */
301 	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
302 
303 	ATF_REQUIRE(buf != MAP_FAILED);
304 #ifdef __FreeBSD__
305 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
306 #else
307 	ATF_REQUIRE(mlock(buf, page) != 0);
308 #endif
309 	ATF_REQUIRE(munmap(buf, page) == 0);
310 }
311 
312 #ifdef __FreeBSD__
313 ATF_TC_CLEANUP(mlock_mmap, tc)
314 {
315 
316 	restore_vm_max_wired();
317 }
318 #endif
319 
320 #ifdef __FreeBSD__
321 ATF_TC_WITH_CLEANUP(mlock_nested);
322 #else
323 ATF_TC(mlock_nested);
324 #endif
325 ATF_TC_HEAD(mlock_nested, tc)
326 {
327 	atf_tc_set_md_var(tc, "descr",
328 	    "Test that consecutive mlock(2) calls succeed");
329 #ifdef __FreeBSD__
330 	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
331 	atf_tc_set_md_var(tc, "require.user", "root");
332 #endif
333 }
334 
335 ATF_TC_BODY(mlock_nested, tc)
336 {
337 	const size_t maxiter = 100;
338 	void *buf;
339 
340 #ifdef __FreeBSD__
341 	/* Set max_wired really really high to avoid EAGAIN */
342 	set_vm_max_wired(INT_MAX);
343 #endif
344 
345 	buf = malloc(page);
346 	ATF_REQUIRE(buf != NULL);
347 
348 	for (size_t i = 0; i < maxiter; i++)
349 		ATF_REQUIRE(mlock(buf, page) == 0);
350 
351 	ATF_REQUIRE(munlock(buf, page) == 0);
352 	free(buf);
353 }
354 
355 #ifdef __FreeBSD__
356 ATF_TC_CLEANUP(mlock_nested, tc)
357 {
358 
359 	restore_vm_max_wired();
360 }
361 #endif
362 
363 ATF_TP_ADD_TCS(tp)
364 {
365 
366 	page = sysconf(_SC_PAGESIZE);
367 	ATF_REQUIRE(page >= 0);
368 
369 	ATF_TP_ADD_TC(tp, mlock_clip);
370 	ATF_TP_ADD_TC(tp, mlock_err);
371 	ATF_TP_ADD_TC(tp, mlock_limits);
372 	ATF_TP_ADD_TC(tp, mlock_mmap);
373 	ATF_TP_ADD_TC(tp, mlock_nested);
374 
375 	return atf_no_error();
376 }
377