t_mlock.c revision 314817 
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
54void set_vm_max_wired(int);
55void restore_vm_max_wired(void);
56#endif
57
58static long page = 0;
59
60ATF_TC(mlock_clip);
61ATF_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
67ATF_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__
86ATF_TC_WITH_CLEANUP(mlock_err);
87#else
88ATF_TC(mlock_err);
89#endif
90ATF_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
100ATF_TC_BODY(mlock_err, tc)
101{
102#ifdef __NetBSD__
103	unsigned long vmin = 0;
104	size_t len = sizeof(vmin);
105#endif
106	void *invalid_ptr;
107	int null_errno = ENOMEM;	/* error expected for NULL */
108	void *buf;
109
110#ifdef __FreeBSD__
111#ifdef VM_MIN_ADDRESS
112	if ((uintptr_t)VM_MIN_ADDRESS > 0)
113		null_errno = EINVAL;	/* NULL is not inside user VM */
114#endif
115	/* Set max_wired really really high to avoid EAGAIN */
116	set_vm_max_wired(INT_MAX);
117#else
118	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
119		atf_tc_fail("failed to read vm.minaddress");
120	/*
121	 * Any bad address must return ENOMEM (for lock & unlock)
122	 */
123	errno = 0;
124	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
125
126	if (vmin > 0)
127		null_errno = EINVAL;	/* NULL is not inside user VM */
128#endif
129
130	errno = 0;
131	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
132
133	errno = 0;
134	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
135
136	errno = 0;
137	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
138
139	errno = 0;
140	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
141
142	errno = 0;
143	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
144
145	buf = malloc(page);
146	ATF_REQUIRE(buf != NULL);
147
148	/*
149	 * unlocking memory that is not locked is an error...
150	 */
151
152	errno = 0;
153	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
154
155	/*
156	 * These are permitted to fail (EINVAL) but do not on NetBSD
157	 */
158	ATF_REQUIRE(mlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
159	ATF_REQUIRE(munlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
160
161	(void)free(buf);
162
163	/*
164	 * Try to create a pointer to an unmapped page - first after current
165	 * brk will likely do.
166	 */
167	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
168	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
169
170	errno = 0;
171	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
172
173	errno = 0;
174	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
175}
176
177#ifdef __FreeBSD__
178ATF_TC_CLEANUP(mlock_err, tc)
179{
180
181	restore_vm_max_wired();
182}
183#endif
184
185ATF_TC(mlock_limits);
186ATF_TC_HEAD(mlock_limits, tc)
187{
188	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
189}
190
191ATF_TC_BODY(mlock_limits, tc)
192{
193	struct rlimit res;
194	void *buf;
195	pid_t pid;
196	int sta;
197
198	buf = malloc(page);
199	ATF_REQUIRE(buf != NULL);
200
201	pid = fork();
202	ATF_REQUIRE(pid >= 0);
203
204	if (pid == 0) {
205
206		for (ssize_t i = page; i >= 2; i -= 100) {
207
208			res.rlim_cur = i - 1;
209			res.rlim_max = i - 1;
210
211			(void)fprintf(stderr, "trying to lock %zd bytes "
212			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
213
214			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
215				_exit(EXIT_FAILURE);
216
217			errno = 0;
218
219#ifdef __FreeBSD__
220			/*
221			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
222			 * FreeBSD does.
223			 *
224			 * See: NetBSD PR # kern/48962 for more details.
225			 */
226			if (mlock(buf, i) != -1 || errno != ENOMEM) {
227#else
228			if (mlock(buf, i) != -1 || errno != EAGAIN) {
229#endif
230				(void)munlock(buf, i);
231				_exit(EXIT_FAILURE);
232			}
233		}
234
235		_exit(EXIT_SUCCESS);
236	}
237
238	(void)wait(&sta);
239
240	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
241		atf_tc_fail("mlock(2) locked beyond system limits");
242
243	free(buf);
244}
245
246#ifdef __FreeBSD__
247ATF_TC_WITH_CLEANUP(mlock_mmap);
248#else
249ATF_TC(mlock_mmap);
250#endif
251ATF_TC_HEAD(mlock_mmap, tc)
252{
253	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
254#ifdef __FreeBSD__
255	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
256	atf_tc_set_md_var(tc, "require.user", "root");
257#endif
258}
259
260ATF_TC_BODY(mlock_mmap, tc)
261{
262#ifdef __NetBSD__
263	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
264#else
265	static const int flags = MAP_ANON | MAP_PRIVATE;
266#endif
267	void *buf;
268
269#ifdef __FreeBSD__
270	/* Set max_wired really really high to avoid EAGAIN */
271	set_vm_max_wired(INT_MAX);
272#endif
273
274	/*
275	 * Make a wired RW mapping and check that mlock(2)
276	 * does not fail for the (already locked) mapping.
277	 */
278	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
279
280	ATF_REQUIRE(buf != MAP_FAILED);
281#ifdef __FreeBSD__
282	/*
283	 * The duplicate mlock call is added to ensure that the call works
284	 * as described above without MAP_WIRED support.
285	 */
286	ATF_REQUIRE(mlock(buf, page) == 0);
287#endif
288	ATF_REQUIRE(mlock(buf, page) == 0);
289	ATF_REQUIRE(munlock(buf, page) == 0);
290	ATF_REQUIRE(munmap(buf, page) == 0);
291	ATF_REQUIRE(munlock(buf, page) != 0);
292
293	/*
294	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
295	 */
296	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
297
298	ATF_REQUIRE(buf != MAP_FAILED);
299#ifdef __FreeBSD__
300	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
301#else
302	ATF_REQUIRE(mlock(buf, page) != 0);
303#endif
304	ATF_REQUIRE(munmap(buf, page) == 0);
305}
306
307#ifdef __FreeBSD__
308ATF_TC_CLEANUP(mlock_mmap, tc)
309{
310
311	restore_vm_max_wired();
312}
313#endif
314
315#ifdef __FreeBSD__
316ATF_TC_WITH_CLEANUP(mlock_nested);
317#else
318ATF_TC(mlock_nested);
319#endif
320ATF_TC_HEAD(mlock_nested, tc)
321{
322	atf_tc_set_md_var(tc, "descr",
323	    "Test that consecutive mlock(2) calls succeed");
324#ifdef __FreeBSD__
325	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
326	atf_tc_set_md_var(tc, "require.user", "root");
327#endif
328}
329
330ATF_TC_BODY(mlock_nested, tc)
331{
332	const size_t maxiter = 100;
333	void *buf;
334
335#ifdef __FreeBSD__
336	/* Set max_wired really really high to avoid EAGAIN */
337	set_vm_max_wired(INT_MAX);
338#endif
339
340	buf = malloc(page);
341	ATF_REQUIRE(buf != NULL);
342
343	for (size_t i = 0; i < maxiter; i++)
344		ATF_REQUIRE(mlock(buf, page) == 0);
345
346	ATF_REQUIRE(munlock(buf, page) == 0);
347	free(buf);
348}
349
350#ifdef __FreeBSD__
351ATF_TC_CLEANUP(mlock_nested, tc)
352{
353
354	restore_vm_max_wired();
355}
356#endif
357
358ATF_TP_ADD_TCS(tp)
359{
360
361	page = sysconf(_SC_PAGESIZE);
362	ATF_REQUIRE(page >= 0);
363
364	ATF_TP_ADD_TC(tp, mlock_clip);
365	ATF_TP_ADD_TC(tp, mlock_err);
366	ATF_TP_ADD_TC(tp, mlock_limits);
367	ATF_TP_ADD_TC(tp, mlock_mmap);
368	ATF_TP_ADD_TC(tp, mlock_nested);
369
370	return atf_no_error();
371}
372