t_mlock.c revision 313498
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/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	void *buf;
182
183#ifdef __FreeBSD__
184#ifdef VM_MIN_ADDRESS
185	if ((uintptr_t)VM_MIN_ADDRESS > 0)
186		null_errno = EINVAL;	/* NULL is not inside user VM */
187#endif
188	/* Set max_wired really really high to avoid EAGAIN */
189	set_vm_max_wired(INT_MAX);
190#else
191	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
192		atf_tc_fail("failed to read vm.minaddress");
193	/*
194	 * Any bad address must return ENOMEM (for lock & unlock)
195	 */
196	errno = 0;
197	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
198
199	if (vmin > 0)
200		null_errno = EINVAL;	/* NULL is not inside user VM */
201#endif
202
203	errno = 0;
204	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
205
206	errno = 0;
207	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
208
209	errno = 0;
210	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
211
212	errno = 0;
213	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
214
215	errno = 0;
216	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
217
218	buf = malloc(page);
219	ATF_REQUIRE(buf != NULL);
220
221	/*
222	 * unlocking memory that is not locked is an error...
223	 */
224
225	errno = 0;
226	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
227
228	/*
229	 * These are permitted to fail (EINVAL) but do not on NetBSD
230	 */
231	ATF_REQUIRE(mlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
232	ATF_REQUIRE(munlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
233
234	(void)free(buf);
235
236	/*
237	 * Try to create a pointer to an unmapped page - first after current
238	 * brk will likely do.
239	 */
240	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
241	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
242
243	errno = 0;
244	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
245
246	errno = 0;
247	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
248}
249
250#ifdef __FreeBSD__
251ATF_TC_CLEANUP(mlock_err, tc)
252{
253
254	restore_vm_max_wired();
255}
256#endif
257
258ATF_TC(mlock_limits);
259ATF_TC_HEAD(mlock_limits, tc)
260{
261	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
262}
263
264ATF_TC_BODY(mlock_limits, tc)
265{
266	struct rlimit res;
267	void *buf;
268	pid_t pid;
269	int sta;
270
271	buf = malloc(page);
272	ATF_REQUIRE(buf != NULL);
273
274	pid = fork();
275	ATF_REQUIRE(pid >= 0);
276
277	if (pid == 0) {
278
279		for (ssize_t i = page; i >= 2; i -= 100) {
280
281			res.rlim_cur = i - 1;
282			res.rlim_max = i - 1;
283
284			(void)fprintf(stderr, "trying to lock %zd bytes "
285			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
286
287			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
288				_exit(EXIT_FAILURE);
289
290			errno = 0;
291
292#ifdef __FreeBSD__
293			/*
294			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
295			 * FreeBSD does.
296			 *
297			 * See: NetBSD PR # kern/48962 for more details.
298			 */
299			if (mlock(buf, i) != -1 || errno != ENOMEM) {
300#else
301			if (mlock(buf, i) != -1 || errno != EAGAIN) {
302#endif
303				(void)munlock(buf, i);
304				_exit(EXIT_FAILURE);
305			}
306		}
307
308		_exit(EXIT_SUCCESS);
309	}
310
311	(void)wait(&sta);
312
313	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
314		atf_tc_fail("mlock(2) locked beyond system limits");
315
316	free(buf);
317}
318
319#ifdef __FreeBSD__
320ATF_TC_WITH_CLEANUP(mlock_mmap);
321#else
322ATF_TC(mlock_mmap);
323#endif
324ATF_TC_HEAD(mlock_mmap, tc)
325{
326	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
327#ifdef __FreeBSD__
328	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
329	atf_tc_set_md_var(tc, "require.user", "root");
330#endif
331}
332
333ATF_TC_BODY(mlock_mmap, tc)
334{
335#ifdef __NetBSD__
336	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
337#else
338	static const int flags = MAP_ANON | MAP_PRIVATE;
339#endif
340	void *buf;
341
342#ifdef __FreeBSD__
343	/* Set max_wired really really high to avoid EAGAIN */
344	set_vm_max_wired(INT_MAX);
345#endif
346
347	/*
348	 * Make a wired RW mapping and check that mlock(2)
349	 * does not fail for the (already locked) mapping.
350	 */
351	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
352
353	ATF_REQUIRE(buf != MAP_FAILED);
354#ifdef __FreeBSD__
355	/*
356	 * The duplicate mlock call is added to ensure that the call works
357	 * as described above without MAP_WIRED support.
358	 */
359	ATF_REQUIRE(mlock(buf, page) == 0);
360#endif
361	ATF_REQUIRE(mlock(buf, page) == 0);
362	ATF_REQUIRE(munlock(buf, page) == 0);
363	ATF_REQUIRE(munmap(buf, page) == 0);
364	ATF_REQUIRE(munlock(buf, page) != 0);
365
366	/*
367	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
368	 */
369	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
370
371	ATF_REQUIRE(buf != MAP_FAILED);
372#ifdef __FreeBSD__
373	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
374#else
375	ATF_REQUIRE(mlock(buf, page) != 0);
376#endif
377	ATF_REQUIRE(munmap(buf, page) == 0);
378}
379
380#ifdef __FreeBSD__
381ATF_TC_CLEANUP(mlock_mmap, tc)
382{
383
384	restore_vm_max_wired();
385}
386#endif
387
388#ifdef __FreeBSD__
389ATF_TC_WITH_CLEANUP(mlock_nested);
390#else
391ATF_TC(mlock_nested);
392#endif
393ATF_TC_HEAD(mlock_nested, tc)
394{
395	atf_tc_set_md_var(tc, "descr",
396	    "Test that consecutive mlock(2) calls succeed");
397#ifdef __FreeBSD__
398	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
399	atf_tc_set_md_var(tc, "require.user", "root");
400#endif
401}
402
403ATF_TC_BODY(mlock_nested, tc)
404{
405	const size_t maxiter = 100;
406	void *buf;
407
408#ifdef __FreeBSD__
409	/* Set max_wired really really high to avoid EAGAIN */
410	set_vm_max_wired(INT_MAX);
411#endif
412
413	buf = malloc(page);
414	ATF_REQUIRE(buf != NULL);
415
416	for (size_t i = 0; i < maxiter; i++)
417		ATF_REQUIRE(mlock(buf, page) == 0);
418
419	ATF_REQUIRE(munlock(buf, page) == 0);
420	free(buf);
421}
422
423#ifdef __FreeBSD__
424ATF_TC_CLEANUP(mlock_nested, tc)
425{
426
427	restore_vm_max_wired();
428}
429#endif
430
431ATF_TP_ADD_TCS(tp)
432{
433
434	page = sysconf(_SC_PAGESIZE);
435	ATF_REQUIRE(page >= 0);
436
437	ATF_TP_ADD_TC(tp, mlock_clip);
438	ATF_TP_ADD_TC(tp, mlock_err);
439	ATF_TP_ADD_TC(tp, mlock_limits);
440	ATF_TP_ADD_TC(tp, mlock_mmap);
441	ATF_TP_ADD_TC(tp, mlock_nested);
442
443	return atf_no_error();
444}
445