1 /*
2 * Copyright (c) 2015 Dmitry V. Levin <ldv@altlinux.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #ifdef HAVE_CONFIG_H
29 # include "config.h"
30 #endif
31
32 #include <stdio.h>
33 #include <string.h>
34 #include <unistd.h>
35 #include <sys/wait.h>
36
37 static int
logit(const char * const str)38 logit(const char *const str)
39 {
40 return pwrite(-1, str, strlen(str), 0) >= 0;
41 }
42
main(int ac,char ** av,char ** ep)43 int main(int ac, char **av, char **ep)
44 {
45 if (ac < 1)
46 return 1;
47 if (ac > 1)
48 return logit(av[1]);
49
50 logit("start");
51
52 int fds[2];
53 (void) close(0);
54 if (pipe(fds)) {
55 perror("pipe");
56 return 77;
57 }
58
59 pid_t pid = fork();
60
61 if (pid < 0) {
62 perror("fork");
63 return 77;
64 }
65
66 if (!pid) {
67 close(fds[1]);
68
69 if (read(0, fds, sizeof(int)))
70 _exit(2);
71
72 char *const args[] = { av[0], (char *) "exec", NULL };
73 if (logit("child") || execve(args[0], args, args + 1))
74 _exit(2);
75 }
76
77 close(0);
78
79 logit("parent");
80 close(fds[1]);
81
82 int status;
83 if (wait(&status) != pid) {
84 perror("wait");
85 return 77;
86 }
87 if (status) {
88 fprintf(stderr, "status = %d\n", status);
89 return 77;
90 }
91
92 logit("finish");
93
94 pid_t ppid = getpid();
95 close(-1);
96 printf("%-5d pwrite64(-1, \"start\", 5, 0) = -1 EBADF (%m)\n"
97 "%-5d pwrite64(-1, \"parent\", 6, 0) = -1 EBADF (%m)\n"
98 "%-5d pwrite64(-1, \"child\", 5, 0) = -1 EBADF (%m)\n"
99 "%-5d pwrite64(-1, \"exec\", 4, 0) = -1 EBADF (%m)\n"
100 "%-5d pwrite64(-1, \"finish\", 6, 0) = -1 EBADF (%m)\n",
101 ppid, ppid, pid, pid, ppid);
102 return 0;
103 }
104