1 /* $NetBSD: t_mincore.c,v 1.15 2020/02/24 12:20:30 rin Exp $ */
2 
3 /*-
4  * Copyright (c) 2011 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 
32 /*-
33  * Copyright (c) 1999 The NetBSD Foundation, Inc.
34  * All rights reserved.
35  *
36  * This code is derived from software contributed to The NetBSD Foundation
37  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
38  * NASA Ames Research Center.
39  *
40  * Redistribution and use in source and binary forms, with or without
41  * modification, are permitted provided that the following conditions
42  * are met:
43  * 1. Redistributions of source code must retain the above copyright
44  *    notice, this list of conditions and the following disclaimer.
45  * 2. Redistributions in binary form must reproduce the above copyright
46  *    notice, this list of conditions and the following disclaimer in the
47  *    documentation and/or other materials provided with the distribution.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
50  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
51  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
52  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
53  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
54  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
55  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
56  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
57  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
58  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
59  * POSSIBILITY OF SUCH DAMAGE.
60  */
61 #include <sys/cdefs.h>
62 __RCSID("$NetBSD: t_mincore.c,v 1.15 2020/02/24 12:20:30 rin Exp $");
63 
64 #include <sys/mman.h>
65 #include <sys/stat.h>
66 #include <sys/shm.h>
67 
68 #include <atf-c.h>
69 #include <errno.h>
70 #include <fcntl.h>
71 #include <kvm.h>
72 #include <signal.h>
73 #include <stdio.h>
74 #include <stdlib.h>
75 #include <string.h>
76 #include <unistd.h>
77 #include <sys/resource.h>
78 
79 static long                   page = 0;
80 static const char   path[] = "mincore";
81 static size_t                 check_residency(void *, size_t);
82 
83 #define ATF_REQUIRE_STRERROR(a) ATF_REQUIRE_MSG(a, " (%s)", strerror(errno))
84 
85 #ifndef PROT_MPROTECT
86 # define PROT_MPROTECT(flags) (0)
87 #endif
88 
89 static size_t
check_residency(void * addr,size_t npgs)90 check_residency(void *addr, size_t npgs)
91 {
92           size_t i, resident;
93           char *vec;
94 
95           vec = malloc(npgs);
96 
97           ATF_REQUIRE(vec != NULL);
98           ATF_REQUIRE(mincore(addr, npgs * page, vec) == 0);
99 
100           for (i = resident = 0; i < npgs; i++) {
101 
102                     if (vec[i] != 0)
103                               resident++;
104 
105 #if 0
106                     (void)fprintf(stderr, "page %p is %sresident\n",
107                         (char *)addr + (i * page), vec[i] ? "" : "not ");
108 #endif
109           }
110 
111           free(vec);
112 
113           return resident;
114 }
115 
116 ATF_TC(mincore_err);
ATF_TC_HEAD(mincore_err,tc)117 ATF_TC_HEAD(mincore_err, tc)
118 {
119           atf_tc_set_md_var(tc, "descr", "Test errors from mincore(2)");
120 }
121 
ATF_TC_BODY(mincore_err,tc)122 ATF_TC_BODY(mincore_err, tc)
123 {
124           char *map, *vec;
125 
126           map = mmap(NULL, page, PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
127           vec = malloc(page);
128 
129           ATF_REQUIRE(vec != NULL);
130           ATF_REQUIRE(map != MAP_FAILED);
131 
132           errno = 0;
133           ATF_REQUIRE_ERRNO(EINVAL, mincore(map, 0, vec) == -1);
134 
135           errno = 0;
136           ATF_REQUIRE_ERRNO(ENOMEM, mincore(0, page, vec) == -1);
137 
138           errno = 0;
139           ATF_REQUIRE_ERRNO(EFAULT, mincore(map, page, (void *)-1) == -1);
140 
141           free(vec);
142           ATF_REQUIRE(munmap(map, page) == 0);
143 }
144 
145 ATF_TC_WITH_CLEANUP(mincore_resid);
ATF_TC_HEAD(mincore_resid,tc)146 ATF_TC_HEAD(mincore_resid, tc)
147 {
148           atf_tc_set_md_var(tc, "descr", "Test page residency with mincore(2)");
149           atf_tc_set_md_var(tc, "require.user", "root");
150 }
151 
ATF_TC_BODY(mincore_resid,tc)152 ATF_TC_BODY(mincore_resid, tc)
153 {
154           void *addr, *addr2, *addr3, *buf;
155           size_t npgs = 0, resident;
156           struct stat st;
157           int fd, rv;
158           struct rlimit rlim;
159 
160           ATF_REQUIRE(getrlimit(RLIMIT_MEMLOCK, &rlim) == 0);
161           /*
162            * Bump the mlock limit to unlimited so the rest of the testcase
163            * passes instead of failing on the mlock call.
164            */
165           rlim.rlim_max = RLIM_INFINITY;
166           rlim.rlim_cur = rlim.rlim_max;
167           ATF_REQUIRE(setrlimit(RLIMIT_MEMLOCK, &rlim) == 0);
168 
169           (void)memset(&st, 0, sizeof(struct stat));
170 
171           fd = open(path, O_RDWR | O_CREAT, 0700);
172           buf = malloc(page * 5);
173 
174           ATF_REQUIRE(fd >= 0);
175           ATF_REQUIRE(buf != NULL);
176 
177           rv = write(fd, buf, page * 5);
178           ATF_REQUIRE(rv >= 0);
179 
180           ATF_REQUIRE(fd >= 0);
181           ATF_REQUIRE(fstat(fd, &st) == 0);
182 
183           addr = mmap(NULL, (size_t)st.st_size, PROT_READ,
184               MAP_FILE | MAP_SHARED, fd, (off_t) 0);
185 
186           ATF_REQUIRE(addr != MAP_FAILED);
187 
188           (void)close(fd);
189 
190           npgs = st.st_size / page;
191 
192           if (st.st_size % page != 0)
193                     npgs++;
194 
195           (void)check_residency(addr, npgs);
196 
197           rv = mlock(addr, npgs * page);
198           if (rv == -1 && errno == EAGAIN)
199                     atf_tc_skip("hit process resource limits");
200           ATF_REQUIRE(munmap(addr, st.st_size) == 0);
201 
202           npgs = 128;
203 
204           addr = mmap(NULL, npgs * page, PROT_READ | PROT_WRITE,
205               MAP_ANON | MAP_PRIVATE | MAP_WIRED, -1, (off_t)0);
206 
207           if (addr == MAP_FAILED)
208                     atf_tc_skip("could not mmap wired anonymous test area, system "
209                         "might be low on memory");
210 
211           ATF_REQUIRE(check_residency(addr, npgs) == npgs);
212           ATF_REQUIRE(munmap(addr, npgs * page) == 0);
213 
214           npgs = 128;
215 
216           addr = mmap(NULL, npgs * page, PROT_READ | PROT_WRITE,
217               MAP_ANON | MAP_PRIVATE, -1, (off_t)0);
218 
219           ATF_REQUIRE(addr != MAP_FAILED);
220 
221           /*
222            * Check that the in-core pages match the locked pages.
223            */
224           ATF_REQUIRE(check_residency(addr, npgs) == 0);
225 
226           errno = 0;
227           if (mlockall(MCL_CURRENT|MCL_FUTURE) != 0 && errno != ENOMEM)
228                     atf_tc_fail("mlockall(2) failed");
229           if (errno == ENOMEM)
230                     atf_tc_skip("mlockall() exceeded process resource limits");
231 
232           resident = check_residency(addr, npgs);
233           if (resident < npgs)
234                     atf_tc_fail("mlockall(MCL_FUTURE) succeeded, still only "
235                         "%zu pages of the newly mapped %zu pages are resident",
236                         resident, npgs);
237 
238           addr2 = mmap(NULL, npgs * page, PROT_READ, MAP_ANON, -1, (off_t)0);
239           addr3 = mmap(NULL, npgs * page, PROT_MPROTECT(PROT_READ) | PROT_NONE,
240               MAP_ANON, -1, (off_t)0);
241 
242           if (addr2 == MAP_FAILED || addr3 == MAP_FAILED)
243                     atf_tc_skip("could not mmap more anonymous test pages with "
244                         "mlockall(MCL_FUTURE) in effect, system "
245                         "might be low on memory");
246 
247           ATF_REQUIRE(check_residency(addr2, npgs) == npgs);
248           ATF_REQUIRE(check_residency(addr3, npgs) == 0);
249           ATF_REQUIRE_STRERROR(mprotect(addr3, npgs * page, PROT_READ) == 0);
250           ATF_REQUIRE(check_residency(addr, npgs) == npgs);
251           ATF_REQUIRE(check_residency(addr2, npgs) == npgs);
252 
253           (void)munlockall();
254 
255           ATF_REQUIRE_STRERROR(madvise(addr2, npgs * page, MADV_FREE) == 0);
256           ATF_REQUIRE(check_residency(addr2, npgs) == 0);
257 
258           (void)memset(addr, 0, npgs * page);
259 
260           ATF_REQUIRE_STRERROR(madvise(addr, npgs * page, MADV_FREE) == 0);
261           ATF_REQUIRE(check_residency(addr, npgs) == 0);
262 
263           (void)munmap(addr, npgs * page);
264           (void)munmap(addr2, npgs * page);
265           (void)munmap(addr3, npgs * page);
266           (void)unlink(path);
267           free(buf);
268 }
269 
ATF_TC_CLEANUP(mincore_resid,tc)270 ATF_TC_CLEANUP(mincore_resid, tc)
271 {
272           (void)unlink(path);
273 }
274 
275 static volatile int sig_caught;
276 
277 static void
sigsys_handler(int signum)278 sigsys_handler(int signum)
279 {
280 
281           sig_caught = signum;
282 }
283 
284 static int
no_kernel_sysvmsg(void)285 no_kernel_sysvmsg(void)
286 {
287           int id;
288           void (*osig)(int);
289 
290           sig_caught = 0;
291           osig = signal(SIGSYS, sigsys_handler);
292           id = shmget(IPC_PRIVATE, page, IPC_CREAT | S_IRUSR | S_IWUSR);
293           if (sig_caught || id == -1)
294                     return 1;
295 
296           (void)shmctl(id, IPC_RMID, 0);
297           (void)signal(SIGSYS, osig);
298 
299           return 0;
300 }
301 
302 ATF_TC(mincore_shmseg);
ATF_TC_HEAD(mincore_shmseg,tc)303 ATF_TC_HEAD(mincore_shmseg, tc)
304 {
305           atf_tc_set_md_var(tc, "descr", "residency of shared memory");
306 }
307 
ATF_TC_BODY(mincore_shmseg,tc)308 ATF_TC_BODY(mincore_shmseg, tc)
309 {
310           size_t npgs = 128;
311           void *addr = NULL;
312           int shmid;
313 
314           if (no_kernel_sysvmsg())
315                     atf_tc_skip("No SYSVSHM in kernel");
316 
317           shmid = shmget(IPC_PRIVATE, npgs * page,
318               IPC_CREAT | S_IRUSR | S_IWUSR);
319 
320           ATF_REQUIRE_STRERROR(shmid != -1);
321 
322           addr = shmat(shmid, NULL, 0);
323 
324           ATF_REQUIRE_STRERROR(addr != NULL);
325           ATF_REQUIRE(check_residency(addr, npgs) == 0);
326 
327           (void)memset(addr, 0xff, npgs * page);
328 
329           ATF_REQUIRE(check_residency(addr, npgs) == npgs);
330           ATF_REQUIRE_STRERROR(madvise(addr, npgs * page, MADV_FREE) == 0);
331 
332           /*
333            * NOTE!  Even though we have MADV_FREE'd the range,
334            * there is another reference (the kernel's) to the
335            * object which owns the pages.  In this case, the
336            * kernel does not simply free the pages, as haphazardly
337            * freeing pages when there are still references to
338            * an object can cause data corruption (say, the other
339            * referencer doesn't expect the pages to be freed,
340            * and is surprised by the subsequent ZFOD).
341            *
342            * Because of this, we simply report the number of
343            * pages still resident, for information only.
344            */
345           npgs = check_residency(addr, npgs);
346 
347           (void)fprintf(stderr, "%zu pages still resident\n", npgs);
348 
349           ATF_REQUIRE_STRERROR(shmdt(addr) == 0);
350           ATF_REQUIRE_STRERROR(shmctl(shmid, IPC_RMID, NULL) == 0);
351 }
352 
ATF_TP_ADD_TCS(tp)353 ATF_TP_ADD_TCS(tp)
354 {
355 
356           page = sysconf(_SC_PAGESIZE);
357           ATF_REQUIRE(page >= 0);
358 
359           ATF_TP_ADD_TC(tp, mincore_err);
360           ATF_TP_ADD_TC(tp, mincore_resid);
361           ATF_TP_ADD_TC(tp, mincore_shmseg);
362 
363           return atf_no_error();
364 }
365