usr/src/test/libc-tests/tests/random/inz_mlock.c

   1 /*
   2  * This file and its contents are supplied under the terms of the
   3  * Common Development and Distribution License ("CDDL"), version 1.0.
   4  * You may only use this file in accordance with the terms of version
   5  * 1.0 of the CDDL.
   6  *
   7  * A full copy of the text of the CDDL should have accompanied this
   8  * source.  A copy of the CDDL is also available via the Internet at
   9  * http://www.illumos.org/license/CDDL.
  10  */
  11
  12 /*
  13  * Copyright (c) 2015, Joyent, Inc.
  14  */
  15
  16 /*
  17  * Verify that using MC_INHERIT_ZERO works just fine when applied to an entire
  18  * region that is mlocked.
  19  */
  20
  21 #include <sys/types.h>
  22 #include <unistd.h>
  23 #include <assert.h>
  24 #include <sys/mman.h>
  25 #include <string.h>
  26 #include <errno.h>
  27 #include <stdlib.h>
  28 #include <wait.h>
  29
  30 int
  31 main(void)
  32 {
  33         void *buf;
  34         pid_t child;
  35         int ret, i;
  36         siginfo_t info;
  37         uint8_t *ubuf;
  38         size_t mapsz = sysconf(_SC_PAGESIZE) * 2;
  39
  40         buf = mmap(NULL, mapsz, PROT_READ | PROT_WRITE,
  41             MAP_PRIVATE | MAP_ANON, -1, 0);
  42         assert(buf != MAP_FAILED);
  43         memset(buf, 'a', mapsz);
  44
  45         ret = mlock(buf, mapsz);
  46         assert(ret == 0);
  47
  48         ret = memcntl(buf, mapsz, MC_INHERIT_ZERO, 0, 0, 0);
  49         assert(ret == 0);
  50
  51         child = fork();
  52         if (child == 0) {
  53                 for (i = 0, ubuf = buf; i < mapsz; i++)
  54                         assert(ubuf[i] == 0);
  55                 exit(0);
  56         }
  57         assert(child != -1);
  58
  59         do {
  60                 ret = waitid(P_PID, child, &info, WEXITED);
  61         } while (ret == -1 && errno == EINTR);
  62         assert(ret == 0);
  63         assert(info.si_pid == child);
  64         assert(info.si_status == 0);
  65
  66         for (i = 0, ubuf = buf; i < mapsz; i++)
  67                 assert(ubuf[i] == 'a');
  68
  69         return (0);
  70 }