usr/src/test/libc-tests/tests/random/inz_child.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 across multiple children.
  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 static int nchild = 5;
  31
  32 int
  33 main(void)
  34 {
  35         void *buf;
  36         pid_t child;
  37         int ret, i;
  38         siginfo_t info;
  39         uint8_t *ubuf;
  40         size_t mapsz = sysconf(_SC_PAGESIZE) * 2;
  41
  42         buf = mmap(NULL, mapsz, PROT_READ | PROT_WRITE,
  43             MAP_PRIVATE | MAP_ANON, -1, 0);
  44         assert(buf != MAP_FAILED);
  45
  46         ret = memcntl(buf, mapsz, MC_INHERIT_ZERO, 0, 0, 0);
  47         assert(ret == 0);
  48
  49 again:
  50         memset(buf, 'a' + nchild, mapsz);
  51         child = fork();
  52         if (child == 0) {
  53                 nchild--;
  54                 for (i = 0, ubuf = buf; i < mapsz; i++)
  55                         assert(ubuf[i] == 0);
  56                 if (nchild != 0)
  57                         goto again;
  58                 exit(0);
  59         }
  60         assert(child != -1);
  61
  62         do {
  63                 ret = waitid(P_PID, child, &info, WEXITED);
  64         } while (ret == -1 && errno == EINTR);
  65         assert(ret == 0);
  66         assert(info.si_pid == child);
  67         assert(info.si_status == 0);
  68
  69         for (i = 0, ubuf = buf; i < mapsz; i++)
  70                 assert(ubuf[i] == 'a' + nchild);
  71
  72         return (0);
  73 }