t_mlock.c revision 309466 
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#if !defined(__aarch64__) && !defined(__riscv__)
180	void *invalid_ptr;
181#endif
182	int null_errno = ENOMEM;	/* error expected for NULL */
183	void *buf;
184
185#ifdef __FreeBSD__
186#ifdef VM_MIN_ADDRESS
187	if ((uintptr_t)VM_MIN_ADDRESS > 0)
188		null_errno = EINVAL;	/* NULL is not inside user VM */
189#endif
190	/* Set max_wired really really high to avoid EAGAIN */
191	set_vm_max_wired(INT_MAX);
192#else
193	if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
194		atf_tc_fail("failed to read vm.minaddress");
195	/*
196	 * Any bad address must return ENOMEM (for lock & unlock)
197	 */
198	errno = 0;
199	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
200
201	if (vmin > 0)
202		null_errno = EINVAL;	/* NULL is not inside user VM */
203#endif
204
205	errno = 0;
206	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
207
208	errno = 0;
209	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
210
211	errno = 0;
212	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
213
214	errno = 0;
215	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
216
217	errno = 0;
218	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
219
220	buf = malloc(page);
221	ATF_REQUIRE(buf != NULL);
222
223	/*
224	 * unlocking memory that is not locked is an error...
225	 */
226
227	errno = 0;
228	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
229
230/* There is no sbrk on AArch64 and RISC-V */
231#if !defined(__aarch64__) && !defined(__riscv__)
232	/*
233	 * These are permitted to fail (EINVAL) but do not on NetBSD
234	 */
235	ATF_REQUIRE(mlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
236	ATF_REQUIRE(munlock((void *)(((uintptr_t)buf) + page/3), page/5) == 0);
237
238	(void)free(buf);
239
240	/*
241	 * Try to create a pointer to an unmapped page - first after current
242	 * brk will likely do.
243	 */
244	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
245	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
246
247	errno = 0;
248	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
249
250	errno = 0;
251	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
252#endif
253}
254
255#ifdef __FreeBSD__
256ATF_TC_CLEANUP(mlock_err, tc)
257{
258
259	restore_vm_max_wired();
260}
261#endif
262
263ATF_TC(mlock_limits);
264ATF_TC_HEAD(mlock_limits, tc)
265{
266	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
267}
268
269ATF_TC_BODY(mlock_limits, tc)
270{
271	struct rlimit res;
272	void *buf;
273	pid_t pid;
274	int sta;
275
276	buf = malloc(page);
277	ATF_REQUIRE(buf != NULL);
278
279	pid = fork();
280	ATF_REQUIRE(pid >= 0);
281
282	if (pid == 0) {
283
284		for (ssize_t i = page; i >= 2; i -= 100) {
285
286			res.rlim_cur = i - 1;
287			res.rlim_max = i - 1;
288
289			(void)fprintf(stderr, "trying to lock %zd bytes "
290			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
291
292			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
293				_exit(EXIT_FAILURE);
294
295			errno = 0;
296
297#ifdef __FreeBSD__
298			/*
299			 * NetBSD doesn't conform to POSIX with ENOMEM requirement;
300			 * FreeBSD does.
301			 *
302			 * See: NetBSD PR # kern/48962 for more details.
303			 */
304			if (mlock(buf, i) != -1 || errno != ENOMEM) {
305#else
306			if (mlock(buf, i) != -1 || errno != EAGAIN) {
307#endif
308				(void)munlock(buf, i);
309				_exit(EXIT_FAILURE);
310			}
311		}
312
313		_exit(EXIT_SUCCESS);
314	}
315
316	(void)wait(&sta);
317
318	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
319		atf_tc_fail("mlock(2) locked beyond system limits");
320
321	free(buf);
322}
323
324#ifdef __FreeBSD__
325ATF_TC_WITH_CLEANUP(mlock_mmap);
326#else
327ATF_TC(mlock_mmap);
328#endif
329ATF_TC_HEAD(mlock_mmap, tc)
330{
331	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
332#ifdef __FreeBSD__
333	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
334	atf_tc_set_md_var(tc, "require.user", "root");
335#endif
336}
337
338ATF_TC_BODY(mlock_mmap, tc)
339{
340#ifdef __NetBSD__
341	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
342#else
343	static const int flags = MAP_ANON | MAP_PRIVATE;
344#endif
345	void *buf;
346
347#ifdef __FreeBSD__
348	/* Set max_wired really really high to avoid EAGAIN */
349	set_vm_max_wired(INT_MAX);
350#endif
351
352	/*
353	 * Make a wired RW mapping and check that mlock(2)
354	 * does not fail for the (already locked) mapping.
355	 */
356	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
357
358	ATF_REQUIRE(buf != MAP_FAILED);
359#ifdef __FreeBSD__
360	/*
361	 * The duplicate mlock call is added to ensure that the call works
362	 * as described above without MAP_WIRED support.
363	 */
364	ATF_REQUIRE(mlock(buf, page) == 0);
365#endif
366	ATF_REQUIRE(mlock(buf, page) == 0);
367	ATF_REQUIRE(munlock(buf, page) == 0);
368	ATF_REQUIRE(munmap(buf, page) == 0);
369	ATF_REQUIRE(munlock(buf, page) != 0);
370
371	/*
372	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
373	 */
374	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
375
376	ATF_REQUIRE(buf != MAP_FAILED);
377#ifdef __FreeBSD__
378	ATF_REQUIRE_ERRNO(ENOMEM, mlock(buf, page) != 0);
379#else
380	ATF_REQUIRE(mlock(buf, page) != 0);
381#endif
382	ATF_REQUIRE(munmap(buf, page) == 0);
383}
384
385#ifdef __FreeBSD__
386ATF_TC_CLEANUP(mlock_mmap, tc)
387{
388
389	restore_vm_max_wired();
390}
391#endif
392
393#ifdef __FreeBSD__
394ATF_TC_WITH_CLEANUP(mlock_nested);
395#else
396ATF_TC(mlock_nested);
397#endif
398ATF_TC_HEAD(mlock_nested, tc)
399{
400	atf_tc_set_md_var(tc, "descr",
401	    "Test that consecutive mlock(2) calls succeed");
402#ifdef __FreeBSD__
403	atf_tc_set_md_var(tc, "require.config", "allow_sysctl_side_effects");
404	atf_tc_set_md_var(tc, "require.user", "root");
405#endif
406}
407
408ATF_TC_BODY(mlock_nested, tc)
409{
410	const size_t maxiter = 100;
411	void *buf;
412
413#ifdef __FreeBSD__
414	/* Set max_wired really really high to avoid EAGAIN */
415	set_vm_max_wired(INT_MAX);
416#endif
417
418	buf = malloc(page);
419	ATF_REQUIRE(buf != NULL);
420
421	for (size_t i = 0; i < maxiter; i++)
422		ATF_REQUIRE(mlock(buf, page) == 0);
423
424	ATF_REQUIRE(munlock(buf, page) == 0);
425	free(buf);
426}
427
428#ifdef __FreeBSD__
429ATF_TC_CLEANUP(mlock_nested, tc)
430{
431
432	restore_vm_max_wired();
433}
434#endif
435
436ATF_TP_ADD_TCS(tp)
437{
438
439	page = sysconf(_SC_PAGESIZE);
440	ATF_REQUIRE(page >= 0);
441
442	ATF_TP_ADD_TC(tp, mlock_clip);
443	ATF_TP_ADD_TC(tp, mlock_err);
444	ATF_TP_ADD_TC(tp, mlock_limits);
445	ATF_TP_ADD_TC(tp, mlock_mmap);
446	ATF_TP_ADD_TC(tp, mlock_nested);
447
448	return atf_no_error();
449}
450