t_mlock.c revision 300680 
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#if !defined(__aarch64__) && !defined(__riscv__)
180	void *invalid_ptr;
181#endif
182	int null_errno = ENOMEM;	/* error expected for NULL */
183
184#ifdef __FreeBSD__
185#ifdef VM_MIN_ADDRESS
186	if ((uintptr_t)VM_MIN_ADDRESS > 0)
187		null_errno = EINVAL;	/* NULL is not inside user VM */
188#endif
189	/* Set max_wired really really high to avoid EAGAIN */
190	set_vm_max_wired(INT_MAX);
191#else
192	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
193		atf_tc_fail("failed to read vm.minaddress");
194
195	if (vmin > 0)
196		null_errno = EINVAL;	/* NULL is not inside user VM */
197#endif
198
199	errno = 0;
200	ATF_REQUIRE_ERRNO(null_errno, mlock(NULL, page) == -1);
201
202	errno = 0;
203	ATF_REQUIRE_ERRNO(null_errno, mlock((char *)0, page) == -1);
204
205	errno = 0;
206	ATF_REQUIRE_ERRNO(EINVAL, mlock((char *)-1, page) == -1);
207
208	errno = 0;
209	ATF_REQUIRE_ERRNO(null_errno, munlock(NULL, page) == -1);
210
211	errno = 0;
212	ATF_REQUIRE_ERRNO(null_errno, munlock((char *)0, page) == -1);
213
214	errno = 0;
215	ATF_REQUIRE_ERRNO(EINVAL, munlock((char *)-1, page) == -1);
216
217/* There is no sbrk on AArch64 and RISC-V */
218#if !defined(__aarch64__) && !defined(__riscv__)
219	/*
220	 * Try to create a pointer to an unmapped page - first after current
221	 * brk will likely do.
222	 */
223	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
224	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
225
226	errno = 0;
227	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
228
229	errno = 0;
230	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
231#endif
232}
233
234#ifdef __FreeBSD__
235ATF_TC_CLEANUP(mlock_err, tc)
236{
237
238	restore_vm_max_wired();
239}
240#endif
241
242ATF_TC(mlock_limits);
243ATF_TC_HEAD(mlock_limits, tc)
244{
245	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
246}
247
248ATF_TC_BODY(mlock_limits, tc)
249{
250	struct rlimit res;
251	void *buf;
252	pid_t pid;
253	int sta;
254
255	buf = malloc(page);
256	ATF_REQUIRE(buf != NULL);
257
258	pid = fork();
259	ATF_REQUIRE(pid >= 0);
260
261	if (pid == 0) {
262
263		for (ssize_t i = page; i >= 2; i -= 100) {
264
265			res.rlim_cur = i - 1;
266			res.rlim_max = i - 1;
267
268			(void)fprintf(stderr, "trying to lock %zd bytes "
269			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
270
271			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
272				_exit(EXIT_FAILURE);
273
274			errno = 0;
275
276#ifdef __FreeBSD__
277			/*
278			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
279			 * FreeBSD does.
280			 *
281			 * See: NetBSD PR # kern/48962 for more details.
282			 */
283			if (mlock(buf, i) != -1 || errno != ENOMEM) {
284#else
285			if (mlock(buf, i) != -1 || errno != EAGAIN) {
286#endif
287				(void)munlock(buf, i);
288				_exit(EXIT_FAILURE);
289			}
290		}
291
292		_exit(EXIT_SUCCESS);
293	}
294
295	(void)wait(&sta);
296
297	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
298		atf_tc_fail("mlock(2) locked beyond system limits");
299
300	free(buf);
301}
302
303#ifdef __FreeBSD__
304ATF_TC_WITH_CLEANUP(mlock_mmap);
305#else
306ATF_TC(mlock_mmap);
307#endif
308ATF_TC_HEAD(mlock_mmap, tc)
309{
310	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
311#ifdef __FreeBSD__
312	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
313	atf_tc_set_md_var(tc, "require.user", "root");
314#endif
315}
316
317ATF_TC_BODY(mlock_mmap, tc)
318{
319#ifdef __NetBSD__
320	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
321#else
322	static const int flags = MAP_ANON | MAP_PRIVATE;
323#endif
324	void *buf;
325
326#ifdef __FreeBSD__
327	/* Set max_wired really really high to avoid EAGAIN */
328	set_vm_max_wired(INT_MAX);
329#endif
330
331	/*
332	 * Make a wired RW mapping and check that mlock(2)
333	 * does not fail for the (already locked) mapping.
334	 */
335	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
336
337	ATF_REQUIRE(buf != MAP_FAILED);
338#ifdef __FreeBSD__
339	/*
340	 * The duplicate mlock call is added to ensure that the call works
341	 * as described above without MAP_WIRED support.
342	 */
343	ATF_REQUIRE(mlock(buf, page) == 0);
344#endif
345	ATF_REQUIRE(mlock(buf, page) == 0);
346	ATF_REQUIRE(munlock(buf, page) == 0);
347	ATF_REQUIRE(munmap(buf, page) == 0);
348	ATF_REQUIRE(munlock(buf, page) != 0);
349
350	/*
351	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
352	 */
353	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
354
355	ATF_REQUIRE(buf != MAP_FAILED);
356#ifdef __FreeBSD__
357	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
358#else
359	ATF_REQUIRE(mlock(buf, page) != 0);
360#endif
361	ATF_REQUIRE(munmap(buf, page) == 0);
362}
363
364#ifdef __FreeBSD__
365ATF_TC_CLEANUP(mlock_mmap, tc)
366{
367
368	restore_vm_max_wired();
369}
370#endif
371
372#ifdef __FreeBSD__
373ATF_TC_WITH_CLEANUP(mlock_nested);
374#else
375ATF_TC(mlock_nested);
376#endif
377ATF_TC_HEAD(mlock_nested, tc)
378{
379	atf_tc_set_md_var(tc, "descr",
380	    "Test that consecutive mlock(2) calls succeed");
381#ifdef __FreeBSD__
382	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
383	atf_tc_set_md_var(tc, "require.user", "root");
384#endif
385}
386
387ATF_TC_BODY(mlock_nested, tc)
388{
389	const size_t maxiter = 100;
390	void *buf;
391
392#ifdef __FreeBSD__
393	/* Set max_wired really really high to avoid EAGAIN */
394	set_vm_max_wired(INT_MAX);
395#endif
396
397	buf = malloc(page);
398	ATF_REQUIRE(buf != NULL);
399
400	for (size_t i = 0; i < maxiter; i++)
401		ATF_REQUIRE(mlock(buf, page) == 0);
402
403	ATF_REQUIRE(munlock(buf, page) == 0);
404	free(buf);
405}
406
407#ifdef __FreeBSD__
408ATF_TC_CLEANUP(mlock_nested, tc)
409{
410
411	restore_vm_max_wired();
412}
413#endif
414
415ATF_TP_ADD_TCS(tp)
416{
417
418	page = sysconf(_SC_PAGESIZE);
419	ATF_REQUIRE(page >= 0);
420
421	ATF_TP_ADD_TC(tp, mlock_clip);
422	ATF_TP_ADD_TC(tp, mlock_err);
423	ATF_TP_ADD_TC(tp, mlock_limits);
424	ATF_TP_ADD_TC(tp, mlock_mmap);
425	ATF_TP_ADD_TC(tp, mlock_nested);
426
427	return atf_no_error();
428}
429