t_mlock.c revision 296750 
1/* $NetBSD: t_mlock.c,v 1.5 2014/02/26 20:49:26 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 1.5 2014/02/26 20:49:26 martin Exp $");
33
34#ifdef __FreeBSD__
35#include <sys/types.h>
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#endif
54
55static long page = 0;
56
57#ifdef __FreeBSD__
58#define	VM_MAX_WIRED "vm.max_wired"
59
60static void
61vm_max_wired_sysctl(int *old_value, int *new_value)
62{
63	size_t old_len;
64	size_t new_len = (new_value == NULL ? 0 : sizeof(int));
65
66	if (old_value == NULL)
67		printf("Setting the new value to %d\n", *new_value);
68	else {
69		ATF_REQUIRE_MSG(sysctlbyname(VM_MAX_WIRED, NULL, &old_len,
70		    new_value, new_len) == 0,
71		    "sysctlbyname(%s) failed: %s", VM_MAX_WIRED, strerror(errno));
72	}
73
74	ATF_REQUIRE_MSG(sysctlbyname(VM_MAX_WIRED, old_value, &old_len,
75	    new_value, new_len) == 0,
76	    "sysctlbyname(%s) failed: %s", VM_MAX_WIRED, strerror(errno));
77
78	if (old_value != NULL)
79		printf("Saved the old value (%d)\n", *old_value);
80}
81
82static void
83set_vm_max_wired(int new_value)
84{
85	FILE *fp;
86	int old_value;
87
88	fp = fopen(VM_MAX_WIRED, "w");
89	if (fp == NULL) {
90		atf_tc_skip("could not open %s for writing: %s",
91		    VM_MAX_WIRED, strerror(errno));
92		return;
93	}
94
95	vm_max_wired_sysctl(&old_value, NULL);
96
97	ATF_REQUIRE_MSG(fprintf(fp, "%d", old_value) > 0,
98	    "saving %s failed", VM_MAX_WIRED);
99
100	fclose(fp);
101
102	vm_max_wired_sysctl(NULL, &new_value);
103}
104
105static void
106restore_vm_max_wired(void)
107{
108	FILE *fp;
109	int saved_max_wired;
110
111	fp = fopen(VM_MAX_WIRED, "r");
112	if (fp == NULL) {
113		perror("fopen failed\n");
114		return;
115	}
116
117	if (fscanf(fp, "%d", &saved_max_wired) != 1) {
118		perror("fscanf failed\n");
119		fclose(fp);
120		return;
121	}
122
123	fclose(fp);
124	printf("old value in %s: %d\n", VM_MAX_WIRED, saved_max_wired);
125
126	if (saved_max_wired == 0) /* This will cripple the test host */
127		return;
128
129	vm_max_wired_sysctl(NULL, &saved_max_wired);
130}
131#endif
132
133ATF_TC(mlock_clip);
134ATF_TC_HEAD(mlock_clip, tc)
135{
136	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
137	    "clips if the clip address is within the entry (PR kern/44788)");
138}
139
140ATF_TC_BODY(mlock_clip, tc)
141{
142	void *buf;
143
144	buf = malloc(page);
145	ATF_REQUIRE(buf != NULL);
146
147	if (page < 1024)
148		atf_tc_skip("page size too small");
149
150	for (size_t i = page; i >= 1; i = i - 1024) {
151		(void)mlock(buf, page - i);
152		(void)munlock(buf, page - i);
153	}
154
155	free(buf);
156}
157
158#ifdef __FreeBSD__
159ATF_TC_WITH_CLEANUP(mlock_err);
160#else
161ATF_TC(mlock_err);
162#endif
163ATF_TC_HEAD(mlock_err, tc)
164{
165	atf_tc_set_md_var(tc, "descr",
166	    "Test error conditions in mlock(2) and munlock(2)");
167#ifdef __FreeBSD__
168	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
169	atf_tc_set_md_var(tc, "require.user", "root");
170#endif
171}
172
173ATF_TC_BODY(mlock_err, tc)
174{
175#ifdef __NetBSD__
176	unsigned long vmin = 0;
177	size_t len = sizeof(vmin);
178#endif
179	void *invalid_ptr;
180	int null_errno = ENOMEM;	/* error expected for NULL */
181
182#ifdef __FreeBSD__
183#ifdef VM_MIN_ADDRESS
184	if ((uintptr_t)VM_MIN_ADDRESS > 0)
185		null_errno = EINVAL;	/* NULL is not inside user VM */
186#endif
187	/* Set max_wired really really high to avoid EAGAIN */
188	set_vm_max_wired(INT_MAX);
189#else
190	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
191		atf_tc_fail("failed to read vm.minaddress");
192
193	if (vmin > 0)
194		null_errno = EINVAL;	/* NULL is not inside user VM */
195#endif
196
197	errno = 0;
198	ATF_REQUIRE_ERRNO(null_errno, mlock(NULL, page) == -1);
199
200	errno = 0;
201	ATF_REQUIRE_ERRNO(null_errno, mlock((char *)0, page) == -1);
202
203	errno = 0;
204	ATF_REQUIRE_ERRNO(EINVAL, mlock((char *)-1, page) == -1);
205
206	errno = 0;
207	ATF_REQUIRE_ERRNO(null_errno, munlock(NULL, page) == -1);
208
209	errno = 0;
210	ATF_REQUIRE_ERRNO(null_errno, munlock((char *)0, page) == -1);
211
212	errno = 0;
213	ATF_REQUIRE_ERRNO(EINVAL, munlock((char *)-1, page) == -1);
214
215	/*
216	 * Try to create a pointer to an unmapped page - first after current
217	 * brk will likely do.
218	 */
219	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
220	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
221
222	errno = 0;
223	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
224
225	errno = 0;
226	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
227}
228
229#ifdef __FreeBSD__
230ATF_TC_CLEANUP(mlock_err, tc)
231{
232
233	restore_vm_max_wired();
234}
235#endif
236
237ATF_TC(mlock_limits);
238ATF_TC_HEAD(mlock_limits, tc)
239{
240	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
241}
242
243ATF_TC_BODY(mlock_limits, tc)
244{
245	struct rlimit res;
246	void *buf;
247	pid_t pid;
248	int sta;
249
250	buf = malloc(page);
251	ATF_REQUIRE(buf != NULL);
252
253	pid = fork();
254	ATF_REQUIRE(pid >= 0);
255
256	if (pid == 0) {
257
258		for (ssize_t i = page; i >= 2; i -= 100) {
259
260			res.rlim_cur = i - 1;
261			res.rlim_max = i - 1;
262
263			(void)fprintf(stderr, "trying to lock %zd bytes "
264			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
265
266			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
267				_exit(EXIT_FAILURE);
268
269			errno = 0;
270
271#ifdef __FreeBSD__
272			/*
273			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
274			 * FreeBSD does.
275			 *
276			 * See: NetBSD PR # kern/48962 for more details.
277			 */
278			if (mlock(buf, i) != -1 || errno != ENOMEM) {
279#else
280			if (mlock(buf, i) != -1 || errno != EAGAIN) {
281#endif
282				(void)munlock(buf, i);
283				_exit(EXIT_FAILURE);
284			}
285		}
286
287		_exit(EXIT_SUCCESS);
288	}
289
290	(void)wait(&sta);
291
292	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
293		atf_tc_fail("mlock(2) locked beyond system limits");
294
295	free(buf);
296}
297
298#ifdef __FreeBSD__
299ATF_TC_WITH_CLEANUP(mlock_mmap);
300#else
301ATF_TC(mlock_mmap);
302#endif
303ATF_TC_HEAD(mlock_mmap, tc)
304{
305	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
306#ifdef __FreeBSD__
307	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
308	atf_tc_set_md_var(tc, "require.user", "root");
309#endif
310}
311
312ATF_TC_BODY(mlock_mmap, tc)
313{
314#ifdef __NetBSD__
315	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
316#else
317	static const int flags = MAP_ANON | MAP_PRIVATE;
318#endif
319	void *buf;
320
321#ifdef __FreeBSD__
322	/* Set max_wired really really high to avoid EAGAIN */
323	set_vm_max_wired(INT_MAX);
324#endif
325
326	/*
327	 * Make a wired RW mapping and check that mlock(2)
328	 * does not fail for the (already locked) mapping.
329	 */
330	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
331
332	ATF_REQUIRE(buf != MAP_FAILED);
333#ifdef __FreeBSD__
334	/*
335	 * The duplicate mlock call is added to ensure that the call works
336	 * as described above without MAP_WIRED support.
337	 */
338	ATF_REQUIRE(mlock(buf, page) == 0);
339#endif
340	ATF_REQUIRE(mlock(buf, page) == 0);
341	ATF_REQUIRE(munlock(buf, page) == 0);
342	ATF_REQUIRE(munmap(buf, page) == 0);
343	ATF_REQUIRE(munlock(buf, page) != 0);
344
345	/*
346	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
347	 */
348	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
349
350	ATF_REQUIRE(buf != MAP_FAILED);
351#ifdef __FreeBSD__
352	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
353#else
354	ATF_REQUIRE(mlock(buf, page) != 0);
355#endif
356	ATF_REQUIRE(munmap(buf, page) == 0);
357}
358
359#ifdef __FreeBSD__
360ATF_TC_CLEANUP(mlock_mmap, tc)
361{
362
363	restore_vm_max_wired();
364}
365#endif
366
367#ifdef __FreeBSD__
368ATF_TC_WITH_CLEANUP(mlock_nested);
369#else
370ATF_TC(mlock_nested);
371#endif
372ATF_TC_HEAD(mlock_nested, tc)
373{
374	atf_tc_set_md_var(tc, "descr",
375	    "Test that consecutive mlock(2) calls succeed");
376#ifdef __FreeBSD__
377	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
378	atf_tc_set_md_var(tc, "require.user", "root");
379#endif
380}
381
382ATF_TC_BODY(mlock_nested, tc)
383{
384	const size_t maxiter = 100;
385	void *buf;
386
387#ifdef __FreeBSD__
388	/* Set max_wired really really high to avoid EAGAIN */
389	set_vm_max_wired(INT_MAX);
390#endif
391
392	buf = malloc(page);
393	ATF_REQUIRE(buf != NULL);
394
395	for (size_t i = 0; i < maxiter; i++)
396		ATF_REQUIRE(mlock(buf, page) == 0);
397
398	ATF_REQUIRE(munlock(buf, page) == 0);
399	free(buf);
400}
401
402#ifdef __FreeBSD__
403ATF_TC_CLEANUP(mlock_nested, tc)
404{
405
406	restore_vm_max_wired();
407}
408#endif
409
410ATF_TP_ADD_TCS(tp)
411{
412
413	page = sysconf(_SC_PAGESIZE);
414	ATF_REQUIRE(page >= 0);
415
416	ATF_TP_ADD_TC(tp, mlock_clip);
417	ATF_TP_ADD_TC(tp, mlock_err);
418	ATF_TP_ADD_TC(tp, mlock_limits);
419	ATF_TP_ADD_TC(tp, mlock_mmap);
420	ATF_TP_ADD_TC(tp, mlock_nested);
421
422	return atf_no_error();
423}
424