Home | History | Annotate | Line # | Download | only in sys 
      1 /* $NetBSD: t_mlock.c,v 1.8 2020/01/24 08:45:16 skrll 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 1.8 2020/01/24 08:45:16 skrll Exp $");
     33 
     34 #include <sys/mman.h>
     35 #include <sys/resource.h>
     36 #include <sys/sysctl.h>
     37 #include <sys/wait.h>
     38 
     39 #include <errno.h>
     40 #include <atf-c.h>
     41 #include <stdint.h>
     42 #include <stdio.h>
     43 #include <stdlib.h>
     44 #include <string.h>
     45 #include <unistd.h>
     46 
     47 static long page = 0;
     48 
     49 ATF_TC(mlock_clip);
     50 ATF_TC_HEAD(mlock_clip, tc)
     51 {
     52 	atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
     53 	    "clips if the clip address is within the entry (PR kern/44788)");
     54 }
     55 
     56 ATF_TC_BODY(mlock_clip, tc)
     57 {
     58 	void *buf;
     59 	int err1, err2;
     60 
     61 	buf = malloc(page);
     62 	ATF_REQUIRE(buf != NULL);
     63 	fprintf(stderr, "mlock_clip: buf = %p (page=%ld)\n", buf, page);
     64 
     65 	if (page < 1024)
     66 		atf_tc_skip("page size too small");
     67 
     68 	for (size_t i = page; i >= 1; i = i - 1024) {
     69 		err1 = mlock(buf, page - i);
     70 		if (err1 != 0)
     71 			fprintf(stderr, "mlock_clip: page=%ld i=%zu,"
     72 			    " mlock(%p, %ld): %s\n", page, i, buf, page - i,
     73 			    strerror(errno));
     74 		err2 = munlock(buf, page - i);
     75 		if (err2 != 0)
     76 			fprintf(stderr, "mlock_clip: page=%ld i=%zu,"
     77 			    " munlock(%p, %ld): %s (mlock %s)\n", page, i,
     78 			    buf, page - i, strerror(errno), err1?"failed":"ok");
     79 	}
     80 
     81 	free(buf);
     82 }
     83 
     84 ATF_TC(mlock_err);
     85 ATF_TC_HEAD(mlock_err, tc)
     86 {
     87 	atf_tc_set_md_var(tc, "descr",
     88 	    "Test error conditions in mlock(2) and munlock(2)");
     89 }
     90 
     91 ATF_TC_BODY(mlock_err, tc)
     92 {
     93 	void *invalid_ptr;
     94 	void *buf;
     95 	int mlock_err, munlock_err;
     96 
     97 	/*
     98 	 * Any bad address must return ENOMEM (for lock & unlock)
     99 	 */
    100 	errno = 0;
    101 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(NULL, page) == -1);
    102 
    103 	errno = 0;
    104 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)0, page) == -1);
    105 
    106 	errno = 0;
    107 	ATF_REQUIRE_ERRNO(ENOMEM, mlock((char *)-1, page) == -1);
    108 
    109 	errno = 0;
    110 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(NULL, page) == -1);
    111 
    112 	errno = 0;
    113 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)0, page) == -1);
    114 
    115 	errno = 0;
    116 	ATF_REQUIRE_ERRNO(ENOMEM, munlock((char *)-1, page) == -1);
    117 
    118 	buf = malloc(page);
    119 	ATF_REQUIRE(buf != NULL);
    120 	fprintf(stderr, "mlock_err: buf = %p (page=%ld)\n", buf, page);
    121 
    122 	/*
    123 	 * unlocking memory that is not locked is an error...
    124 	 */
    125 
    126 	errno = 0;
    127 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(buf, page) == -1);
    128 
    129 	/*
    130 	 * These are permitted to fail (EINVAL) but do not on NetBSD
    131 	 */
    132 	mlock_err = mlock((void *)(((uintptr_t)buf) + page/3), page/5);
    133 	if (mlock_err != 0)
    134 	    fprintf(stderr, "mlock_err: mlock(%p, %ld): %d [%d] %s\n",
    135 		(void *)(((uintptr_t)buf) + page/3), page/5, mlock_err,
    136 		errno, strerror(errno));
    137 	ATF_REQUIRE(mlock_err == 0);
    138 	munlock_err= munlock((void *)(((uintptr_t)buf) + page/3), page/5);
    139 	if (munlock_err != 0)
    140 	    fprintf(stderr, "mlock_err: munlock(%p, %ld): %d [%d] %s\n",
    141 		(void *)(((uintptr_t)buf) + page/3), page/5, munlock_err,
    142 		errno, strerror(errno));
    143 	ATF_REQUIRE(munlock_err == 0);
    144 
    145 	(void)free(buf);
    146 
    147 	/*
    148 	 * Try to create a pointer to an unmapped page - first after current
    149 	 * brk will likely do.
    150 	 */
    151 	invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
    152 	printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
    153 
    154 	errno = 0;
    155 	ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
    156 
    157 	errno = 0;
    158 	ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
    159 }
    160 
    161 ATF_TC(mlock_limits);
    162 ATF_TC_HEAD(mlock_limits, tc)
    163 {
    164 	atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
    165 }
    166 
    167 ATF_TC_BODY(mlock_limits, tc)
    168 {
    169 	struct rlimit res;
    170 	void *buf;
    171 	pid_t pid;
    172 	int sta;
    173 
    174 	buf = malloc(page);
    175 	ATF_REQUIRE(buf != NULL);
    176 	fprintf(stderr, "mlock_limits: buf = %p (page=%ld)\n", buf, page);
    177 
    178 	pid = fork();
    179 	ATF_REQUIRE(pid >= 0);
    180 
    181 	if (pid == 0) {
    182 
    183 		for (ssize_t i = page; i >= 2; i -= 100) {
    184 
    185 			res.rlim_cur = i - 1;
    186 			res.rlim_max = i - 1;
    187 
    188 			(void)fprintf(stderr, "trying to lock %zu bytes "
    189 			    "with %zu byte limit\n", i, (size_t)res.rlim_cur);
    190 
    191 			if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
    192 				_exit(EXIT_FAILURE);
    193 
    194 			errno = 0;
    195 
    196 			if ((sta = mlock(buf, i)) != -1 || errno != EAGAIN) {
    197 				fprintf(stderr, "mlock(%p, %zu): %d [%d] %s\n",
    198 				    buf, i, sta, errno, strerror(errno));
    199 				(void)munlock(buf, i);
    200 				_exit(EXIT_FAILURE);
    201 			}
    202 		}
    203 
    204 		_exit(EXIT_SUCCESS);
    205 	}
    206 
    207 	(void)wait(&sta);
    208 
    209 	if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
    210 		atf_tc_fail("mlock(2) locked beyond system limits");
    211 
    212 	free(buf);
    213 }
    214 
    215 ATF_TC(mlock_mmap);
    216 ATF_TC_HEAD(mlock_mmap, tc)
    217 {
    218 	atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
    219 }
    220 
    221 ATF_TC_BODY(mlock_mmap, tc)
    222 {
    223 	static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
    224 	void *buf;
    225 
    226 	/*
    227 	 * Make a wired RW mapping and check that mlock(2)
    228 	 * does not fail for the (already locked) mapping.
    229 	 */
    230 	buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
    231 
    232 	if (buf == MAP_FAILED)
    233 		fprintf(stderr,
    234 		    "mlock_mmap: mmap(NULL, %ld, %#x, %#x, -1, 0): MAP_FAILED"
    235 		    " [%d] %s\n", page, PROT_READ | PROT_WRITE, flags, errno,
    236 		    strerror(errno));
    237 
    238 	ATF_REQUIRE(buf != MAP_FAILED);
    239 
    240 	fprintf(stderr, "mlock_mmap: buf=%p, page=%ld\n", buf, page);
    241 
    242 	ATF_REQUIRE(mlock(buf, page) == 0);
    243 	ATF_REQUIRE(munlock(buf, page) == 0);
    244 	ATF_REQUIRE(munmap(buf, page) == 0);
    245 	ATF_REQUIRE(munlock(buf, page) != 0);
    246 
    247 	fprintf(stderr, "mlock_mmap: first test succeeded\n");
    248 
    249 	/*
    250 	 * But it should be impossible to mlock(2) a PROT_NONE mapping.
    251 	 */
    252 	buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
    253 
    254 	if (buf == MAP_FAILED)
    255 		fprintf(stderr,
    256 		    "mlock_mmap: mmap(NULL, %ld, %#x, %#x, -1, 0): MAP_FAILED"
    257 		    " [%d] %s\n", page, PROT_NONE, flags, errno,
    258 		    strerror(errno));
    259 
    260 	ATF_REQUIRE(buf != MAP_FAILED);
    261 	ATF_REQUIRE(mlock(buf, page) != 0);
    262 	ATF_REQUIRE(munmap(buf, page) == 0);
    263 
    264 	fprintf(stderr, "mlock_mmap: second test succeeded\n");
    265 }
    266 
    267 ATF_TC(mlock_nested);
    268 ATF_TC_HEAD(mlock_nested, tc)
    269 {
    270 	atf_tc_set_md_var(tc, "descr",
    271 	    "Test that consecutive mlock(2) calls succeed");
    272 }
    273 
    274 ATF_TC_BODY(mlock_nested, tc)
    275 {
    276 	const size_t maxiter = 100;
    277 	void *buf;
    278 	int err;
    279 
    280 	buf = malloc(page);
    281 	ATF_REQUIRE(buf != NULL);
    282 	fprintf(stderr, "mlock_nested: buf = %p (page=%ld)\n", buf, page);
    283 
    284 	for (size_t i = 0; i < maxiter; i++) {
    285 		err = mlock(buf, page);
    286 		if (err != 0)
    287 		    fprintf(stderr,
    288 		    "mlock_nested: i=%zu (of %zu) mlock(%p, %ld): %d [%d] %s\n",
    289 			i, maxiter, buf, page, err, errno, strerror(errno));
    290 		ATF_REQUIRE(err == 0);
    291 	}
    292 
    293 	err = munlock(buf, page);
    294 	if (err != 0)
    295 		fprintf(stderr, "mlock_nested: munlock(%p, %ld): %d [%d] %s\n",
    296 		    buf, page, err, errno, strerror(errno));
    297 	ATF_REQUIRE(err == 0);
    298 	free(buf);
    299 }
    300 
    301 ATF_TP_ADD_TCS(tp)
    302 {
    303 
    304 	page = sysconf(_SC_PAGESIZE);
    305 	ATF_REQUIRE(page >= 0);
    306 
    307 	ATF_TP_ADD_TC(tp, mlock_clip);
    308 	ATF_TP_ADD_TC(tp, mlock_err);
    309 	ATF_TP_ADD_TC(tp, mlock_limits);
    310 	ATF_TP_ADD_TC(tp, mlock_mmap);
    311 	ATF_TP_ADD_TC(tp, mlock_nested);
    312 
    313 	return atf_no_error();
    314 }
    315