1 /*
2 * Copyright (c) International Business Machines Corp., 2001
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
12 * the GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 *
19 * NAME
20 * fork12.c
21 *
22 * DESCRIPTION
23 * Check that all children inherit parent's file descriptor
24 *
25 * ALGORITHM
26 * Parent forks processes until -1 is returned.$
27 *
28 * USAGE
29 * fork12
30 * ** CAUTION ** Can hang your machine, esp prior to 2.4.19
31 *
32 * HISTORY
33 * 07/2001 Ported by Wayne Boyer
34 * 07/2002 Split from fork07 as a test case to exhaust available pids.
35 *
36 * RESTRICTIONS
37 * Should be run as root to avoid resource limits.$
38 * Should not be run with other test programs because it tries to
39 * use all available pids.
40 */
41
42 #include <stdio.h>
43 #include <sys/wait.h>
44 #include <errno.h>
45 #include <string.h>
46 #include "test.h"
47
48 char *TCID = "fork12";
49 int TST_TOTAL = 1;
50
51 static void setup(void);
52 static void cleanup(void);
53 static void fork12_sigs(int signum);
54
main(int ac,char ** av)55 int main(int ac, char **av)
56 {
57 int forks, pid1, fork_errno, waitstatus;
58 int ret, status;
59 int lc;
60
61 tst_parse_opts(ac, av, NULL, NULL);
62
63 setup();
64
65 for (lc = 0; TEST_LOOPING(lc); lc++) {
66 tst_count = 0;
67
68 tst_resm(TINFO, "Forking as many kids as possible");
69 forks = 0;
70 while ((pid1 = fork()) != -1) {
71 if (pid1 == 0) { /* child */
72 pause();
73 exit(0);
74 }
75 forks++;
76 ret = waitpid(-1, &status, WNOHANG);
77 if (ret < 0)
78 tst_brkm(TBROK, cleanup,
79 "waitpid failed %d: %s\n", errno,
80 strerror(errno));
81 if (ret > 0) {
82 /* a child may be killed by OOM killer */
83 if (WTERMSIG(status) == SIGKILL)
84 break;
85 tst_brkm(TBROK, cleanup,
86 "child exit with error code %d or signal %d",
87 WEXITSTATUS(status), WTERMSIG(status));
88 }
89 }
90 fork_errno = errno;
91
92 /* parent */
93 tst_resm(TINFO, "Number of processes forked is %d", forks);
94 tst_resm(TPASS, "fork() eventually failed with %d: %s",
95 fork_errno, strerror(fork_errno));
96 /* collect our kids */
97 /*
98 * Introducing a sleep(3) to make sure all children are
99 * at pause() when SIGQUIT is sent to them
100 */
101 sleep(3);
102 kill(0, SIGQUIT);
103 while (wait(&waitstatus) > 0) ;
104
105 }
106
107 cleanup();
108 tst_exit();
109 }
110
setup(void)111 static void setup(void)
112 {
113 tst_sig(FORK, fork12_sigs, cleanup);
114 TEST_PAUSE;
115 }
116
cleanup(void)117 static void cleanup(void)
118 {
119 int waitstatus;
120
121 /* collect our kids */
122 kill(0, SIGQUIT);
123 while (wait(&waitstatus) > 0) ;
124 }
125
fork12_sigs(int signum)126 static void fork12_sigs(int signum)
127 {
128 if (signum == SIGQUIT) {
129 /* Children will continue, parent will ignore */
130 } else {
131 tst_brkm(TBROK, cleanup,
132 "Unexpected signal %d received.", signum);
133 }
134 }
135