tests/lib/libc/sys/t_mlock.c

   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 #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 <unistd.h>
  45
  46 static long page = 0;
  47
  48 ATF_TC(mlock_clip);
  49 ATF_TC_HEAD(mlock_clip, tc)
  50 {
  51         atf_tc_set_md_var(tc, "descr", "Test with mlock(2) that UVM only "
  52             "clips if the clip address is within the entry (PR kern/44788)");
  53 }
  54
  55 ATF_TC_BODY(mlock_clip, tc)
  56 {
  57         void *buf;
  58
  59         buf = malloc(page);
  60         ATF_REQUIRE(buf != NULL);
  61
  62         if (page < 1024)
  63                 atf_tc_skip("page size too small");
  64
  65         for (size_t i = page; i >= 1; i = i - 1024) {
  66                 (void)mlock(buf, page - i);
  67                 (void)munlock(buf, page - i);
  68         }
  69
  70         free(buf);
  71 }
  72
  73 ATF_TC(mlock_err);
  74 ATF_TC_HEAD(mlock_err, tc)
  75 {
  76         atf_tc_set_md_var(tc, "descr",
  77             "Test error conditions in mlock(2) and munlock(2)");
  78 }
  79
  80 ATF_TC_BODY(mlock_err, tc)
  81 {
  82         unsigned long vmin = 0;
  83         size_t len = sizeof(vmin);
  84         void *invalid_ptr;
  85         int null_errno = ENOMEM;        /* error expected for NULL */
  86
  87         if (sysctlbyname("vm.minaddress", &vmin, &len, NULL, 0) != 0)
  88                 atf_tc_fail("failed to read vm.minaddress");
  89
  90         if (vmin > 0)
  91                 null_errno = EINVAL;    /* NULL is not inside user VM */
  92
  93         errno = 0;
  94         ATF_REQUIRE_ERRNO(null_errno, mlock(NULL, page) == -1);
  95
  96         errno = 0;
  97         ATF_REQUIRE_ERRNO(null_errno, mlock((char *)0, page) == -1);
  98
  99         errno = 0;
 100         ATF_REQUIRE_ERRNO(EINVAL, mlock((char *)-1, page) == -1);
 101
 102         errno = 0;
 103         ATF_REQUIRE_ERRNO(null_errno, munlock(NULL, page) == -1);
 104
 105         errno = 0;
 106         ATF_REQUIRE_ERRNO(null_errno, munlock((char *)0, page) == -1);
 107
 108         errno = 0;
 109         ATF_REQUIRE_ERRNO(EINVAL, munlock((char *)-1, page) == -1);
 110
 111         /*
 112          * Try to create a pointer to an unmapped page - first after current
 113          * brk will likely do.
 114          */
 115         invalid_ptr = (void*)(((uintptr_t)sbrk(0)+page) & ~(page-1));
 116         printf("testing with (hopefully) invalid pointer %p\n", invalid_ptr);
 117
 118         errno = 0;
 119         ATF_REQUIRE_ERRNO(ENOMEM, mlock(invalid_ptr, page) == -1);
 120
 121         errno = 0;
 122         ATF_REQUIRE_ERRNO(ENOMEM, munlock(invalid_ptr, page) == -1);
 123 }
 124
 125 ATF_TC(mlock_limits);
 126 ATF_TC_HEAD(mlock_limits, tc)
 127 {
 128         atf_tc_set_md_var(tc, "descr", "Test system limits with mlock(2)");
 129 }
 130
 131 ATF_TC_BODY(mlock_limits, tc)
 132 {
 133         struct rlimit res;
 134         void *buf;
 135         pid_t pid;
 136         int sta;
 137
 138         buf = malloc(page);
 139         ATF_REQUIRE(buf != NULL);
 140
 141         pid = fork();
 142         ATF_REQUIRE(pid >= 0);
 143
 144         if (pid == 0) {
 145
 146                 for (ssize_t i = page; i >= 2; i -= 100) {
 147
 148                         res.rlim_cur = i - 1;
 149                         res.rlim_max = i - 1;
 150
 151                         (void)fprintf(stderr, "trying to lock %zd bytes "
 152                             "with %zu byte limit\n", i, (size_t)res.rlim_cur);
 153
 154                         if (setrlimit(RLIMIT_MEMLOCK, &res) != 0)
 155                                 _exit(EXIT_FAILURE);
 156
 157                         errno = 0;
 158
 159                         if (mlock(buf, i) != -1 || errno != EAGAIN) {
 160                                 (void)munlock(buf, i);
 161                                 _exit(EXIT_FAILURE);
 162                         }
 163                 }
 164
 165                 _exit(EXIT_SUCCESS);
 166         }
 167
 168         (void)wait(&sta);
 169
 170         if (WIFEXITED(sta) == 0 || WEXITSTATUS(sta) != EXIT_SUCCESS)
 171                 atf_tc_fail("mlock(2) locked beyond system limits");
 172
 173         free(buf);
 174 }
 175
 176 ATF_TC(mlock_mmap);
 177 ATF_TC_HEAD(mlock_mmap, tc)
 178 {
 179         atf_tc_set_md_var(tc, "descr", "Test mlock(2)-mmap(2) interaction");
 180 }
 181
 182 ATF_TC_BODY(mlock_mmap, tc)
 183 {
 184         static const int flags = MAP_ANON | MAP_PRIVATE | MAP_WIRED;
 185         void *buf;
 186
 187         /*
 188          * Make a wired RW mapping and check that mlock(2)
 189          * does not fail for the (already locked) mapping.
 190          */
 191         buf = mmap(NULL, page, PROT_READ | PROT_WRITE, flags, -1, 0);
 192
 193         ATF_REQUIRE(buf != MAP_FAILED);
 194         ATF_REQUIRE(mlock(buf, page) == 0);
 195         ATF_REQUIRE(munlock(buf, page) == 0);
 196         ATF_REQUIRE(munmap(buf, page) == 0);
 197         ATF_REQUIRE(munlock(buf, page) != 0);
 198
 199         /*
 200          * But it should be impossible to mlock(2) a PROT_NONE mapping.
 201          */
 202         buf = mmap(NULL, page, PROT_NONE, flags, -1, 0);
 203
 204         ATF_REQUIRE(buf != MAP_FAILED);
 205         ATF_REQUIRE(mlock(buf, page) != 0);
 206         ATF_REQUIRE(munmap(buf, page) == 0);
 207 }
 208
 209 ATF_TC(mlock_nested);
 210 ATF_TC_HEAD(mlock_nested, tc)
 211 {
 212         atf_tc_set_md_var(tc, "descr",
 213             "Test that consecutive mlock(2) calls succeed");
 214 }
 215
 216 ATF_TC_BODY(mlock_nested, tc)
 217 {
 218         const size_t maxiter = 100;
 219         void *buf;
 220
 221         buf = malloc(page);
 222         ATF_REQUIRE(buf != NULL);
 223
 224         for (size_t i = 0; i < maxiter; i++)
 225                 ATF_REQUIRE(mlock(buf, page) == 0);
 226
 227         ATF_REQUIRE(munlock(buf, page) == 0);
 228         free(buf);
 229 }
 230
 231 ATF_TP_ADD_TCS(tp)
 232 {
 233
 234         page = sysconf(_SC_PAGESIZE);
 235         ATF_REQUIRE(page >= 0);
 236
 237         ATF_TP_ADD_TC(tp, mlock_clip);
 238         ATF_TP_ADD_TC(tp, mlock_err);
 239         ATF_TP_ADD_TC(tp, mlock_limits);
 240         ATF_TP_ADD_TC(tp, mlock_mmap);
 241         ATF_TP_ADD_TC(tp, mlock_nested);
 242
 243         return atf_no_error();
 244 }