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 then gets split in half, hence creating new segments.
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
main(void)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) * 8;
39 size_t spltsz = sysconf(_SC_PAGESIZE) * 4;
40 size_t spltoff = 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 memset(buf, 'a', mapsz);
46
47 ret = memcntl(buf, mapsz, MC_INHERIT_ZERO, 0, 0, 0);
48 assert(ret == 0);
49
50 ret = munmap(buf + spltoff, spltsz);
51 assert(ret == 0);
52
53 child = fork();
54 if (child == 0) {
55 ubuf = buf;
56 for (i = 0; i < spltoff; i++)
57 assert(ubuf[i] == 0);
58 for (i = spltoff + spltsz; i < mapsz; i++)
59 assert(ubuf[i] == 0);
60 exit(0);
61 }
62 assert(child != -1);
63
64 do {
65 ret = waitid(P_PID, child, &info, WEXITED);
66 } while (ret == -1 && errno == EINTR);
67 assert(ret == 0);
68 assert(info.si_pid == child);
69 assert(info.si_status == 0);
70
71 ubuf = buf;
72 for (i = 0; i < spltoff; i++)
73 assert(ubuf[i] == 'a');
74 for (i = spltoff + spltsz; i < mapsz; i++)
75 assert(ubuf[i] == 'a');
76
77 return (0);
78 }
79