1 /* Test for vfork functions.
2    Copyright (C) 2004-2022 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <unistd.h>
23 #include <sys/types.h>
24 #include <sys/wait.h>
25 
26 /* This test relies on non-POSIX functionality since the child
27    processes call write and getpid.  */
28 static int
do_test(void)29 do_test (void)
30 {
31   int result = 0;
32   int fd[2];
33 
34   if (pipe (fd) == -1)
35     {
36       puts ("pipe failed");
37       return 1;
38     }
39 
40   /* First vfork() without previous getpid().  */
41   pid_t p1;
42   if ((p1 = vfork ()) == 0)
43     {
44       pid_t p = getpid ();
45       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
46     }
47   else if (p1 == -1)
48     {
49       puts ("1st vfork failed");
50       result = 1;
51     }
52 
53   pid_t p2 = 0;
54   if (TEMP_FAILURE_RETRY (read (fd[0], &p2, sizeof (pid_t))) != sizeof (pid_t))
55     {
56       puts ("1st read failed");
57       result = 1;
58     }
59   int r;
60   if (TEMP_FAILURE_RETRY (waitpid (p1, &r, 0)) != p1)
61     {
62       puts ("1st waitpid failed");
63       result = 1;
64     }
65   else if (r != 0)
66     {
67       puts ("write in 1st child failed");
68       result = 1;
69     }
70 
71   /* Main process' ID.  */
72   pid_t p0 = getpid ();
73 
74   /* vfork() again, but after a getpid() in the main process.  */
75   pid_t p3;
76   if ((p3 = vfork ()) == 0)
77     {
78       pid_t p = getpid ();
79       _exit (TEMP_FAILURE_RETRY (write (fd[1], &p, sizeof (p))) != sizeof (p));
80     }
81   else if (p1 == -1)
82     {
83       puts ("2nd vfork failed");
84       result = 1;
85     }
86 
87   pid_t p4;
88   if (TEMP_FAILURE_RETRY (read (fd[0], &p4, sizeof (pid_t))) != sizeof (pid_t))
89     {
90       puts ("2nd read failed");
91       result = 1;
92     }
93   if (TEMP_FAILURE_RETRY (waitpid (p3, &r, 0)) != p3)
94     {
95       puts ("2nd waitpid failed");
96       result = 1;
97     }
98   else if (r != 0)
99     {
100       puts ("write in 2nd child failed");
101       result = 1;
102     }
103 
104   /* And getpid in the main process again.  */
105   pid_t p5 = getpid ();
106 
107   /* Analysis of the results.  */
108   if (p0 != p5)
109     {
110       printf ("p0(%ld) != p5(%ld)\n", (long int) p0, (long int) p5);
111       result = 1;
112     }
113 
114   if (p0 == p1)
115     {
116       printf ("p0(%ld) == p1(%ld)\n", (long int) p0, (long int) p1);
117       result = 1;
118     }
119 
120   if (p1 != p2)
121     {
122       printf ("p1(%ld) != p2(%ld)\n", (long int) p1, (long int) p2);
123       result = 1;
124     }
125 
126   if (p0 == p3)
127     {
128       printf ("p0(%ld) == p3(%ld)\n", (long int) p0, (long int) p3);
129       result = 1;
130     }
131 
132   if (p3 != p4)
133     {
134       printf ("p3(%ld) != p4(%ld)\n", (long int) p3, (long int) p4);
135       result = 1;
136     }
137 
138   close (fd[0]);
139   close (fd[1]);
140 
141   if (result == 0)
142     puts ("All OK");
143 
144   return result;
145 }
146 
147 #define TEST_FUNCTION do_test ()
148 #include "../test-skeleton.c"
149