1 /*
2 *
3 * Copyright (c) International Business Machines Corp., 2002
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program 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
13 * the GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20 /*
21 * NAME
22 * pipe04.c
23 *
24 * DESCRIPTION
25 * Check that processes are killable, even when they are still writing
26 * data to a pipe.
27 *
28 * ALGORITHM
29 * 1. Open a pipe
30 * 2. fork a two children that will write to the pipe
31 * 3. read a bit from both children
32 * 3. kill both children and wait to make sure they die
33 *
34 * USAGE: <for command-line>
35 * pipe04 [-c n] [-f] [-i n] [-I x] [-P x] [-t]
36 * where, -c n : Run n copies concurrently.
37 * -f : Turn off functionality Testing.
38 * -i n : Execute test n times.
39 * -I x : Execute test for x seconds.
40 * -P x : Pause for x seconds between iterations.
41 * -t : Turn on syscall timing.
42 *
43 * HISTORY
44 * 11/2002 Ported by Paul Larson
45 */
46 #include <unistd.h>
47 #include <errno.h>
48 #include <signal.h>
49 #include <sys/types.h>
50 #include <sys/wait.h>
51 #include "test.h"
52
53 char *TCID = "pipe04";
54 int TST_TOTAL = 1;
55
56 int fildes[2]; /* fds for pipe read and write */
57
58 void setup(void);
59 void cleanup(void);
60 void c1func(void);
61 void c2func(void);
62 void alarmfunc(int);
63
do_read(int fd,void * buf,size_t count)64 ssize_t do_read(int fd, void *buf, size_t count)
65 {
66 ssize_t n;
67
68 do {
69 n = read(fd, buf, count);
70 } while (n < 0 && errno == EINTR);
71
72 return n;
73 }
74
main(int ac,char ** av)75 int main(int ac, char **av)
76 {
77 int lc;
78 pid_t c1pid, c2pid;
79 int wtstatus;
80 int bytesread;
81 int acnt = 0, bcnt = 0;
82
83 char rbuf[BUFSIZ];
84
85 tst_parse_opts(ac, av, NULL, NULL);
86 #ifdef UCLINUX
87 maybe_run_child(&c1func, "ndd", 1, &fildes[0], &fildes[1]);
88 maybe_run_child(&c2func, "ndd", 2, &fildes[0], &fildes[1]);
89 #endif
90
91 setup();
92
93 for (lc = 0; TEST_LOOPING(lc); lc++) {
94
95 /* reset tst_count in case we are looping */
96 tst_count = 0;
97
98 if (pipe(fildes) == -1)
99 tst_brkm(TBROK, cleanup, "pipe() failed - errno %d",
100 errno);
101
102 if ((c1pid = FORK_OR_VFORK()) == -1)
103 tst_brkm(TBROK, cleanup, "fork() failed - "
104 "errno %d", errno);
105 if (c1pid == 0)
106 #ifdef UCLINUX
107 if (self_exec(av[0], "ndd", 1, fildes[0], fildes[1]) <
108 0) {
109 tst_brkm(TBROK, cleanup, "self_exec failed");
110 }
111 #else
112 c1func();
113 #endif
114 if ((c2pid = FORK_OR_VFORK()) == -1)
115 tst_brkm(TBROK, cleanup, "fork() failed - "
116 "errno %d", errno);
117 if (c2pid == 0)
118 #ifdef UCLINUX
119 if (self_exec(av[0], "ndd", 2, fildes[0], fildes[1]) <
120 0) {
121 tst_brkm(TBROK, cleanup, "self_exec failed");
122 }
123 #else
124 c2func();
125 #endif
126
127 /* PARENT */
128 if (close(fildes[1]) == -1)
129 tst_resm(TWARN, "Could not close fildes[1] - errno %d",
130 errno);
131 /*
132 * Read a bit from the children first
133 */
134 while ((acnt < 100) && (bcnt < 100)) {
135 bytesread = do_read(fildes[0], rbuf, sizeof(rbuf));
136 if (bytesread < 0) {
137 tst_resm(TFAIL, "Unable to read from pipe, "
138 "errno=%d", errno);
139 break;
140 }
141 switch (rbuf[1]) {
142 case 'A':
143 acnt++;
144 break;
145 case 'b':
146 bcnt++;
147 break;
148 default:
149 tst_resm(TFAIL, "Got bogus '%c' "
150 "character", rbuf[1]);
151 break;
152 }
153 }
154
155 /*
156 * Try to kill the children
157 */
158 if (kill(c1pid, SIGKILL) == -1)
159 tst_resm(TFAIL, "failed to kill child 1, errno=%d",
160 errno);
161 if (kill(c2pid, SIGKILL) == -1)
162 tst_resm(TFAIL, "failed to kill child 1, errno=%d",
163 errno);
164
165 /*
166 * Set action for the alarm
167 */
168 if (signal(SIGALRM, alarmfunc) == SIG_ERR)
169 tst_resm(TWARN | TERRNO, "call to signal failed");
170 /*
171 * Set an alarm for 60 seconds just in case the child
172 * processes don't die
173 */
174 alarm(60);
175 if (waitpid(c1pid, &wtstatus, 0) != -1) {
176 if (wtstatus != SIGKILL)
177 tst_resm(TFAIL | TERRNO,
178 "unexpected wait status " "%d",
179 wtstatus);
180 else
181 tst_resm(TPASS, "Child 1 killed while "
182 "writing to a pipe");
183 }
184 if (waitpid(c2pid, &wtstatus, 0) != -1) {
185 if (!WIFSIGNALED(wtstatus) ||
186 WTERMSIG(wtstatus) != SIGKILL)
187 tst_resm(TFAIL | TERRNO,
188 "unexpected wait status " "%d",
189 wtstatus);
190 else
191 tst_resm(TPASS, "Child 2 killed while "
192 "writing to a pipe");
193 }
194 if (alarm(0) <= 0)
195 tst_resm(TWARN, "call to alarm(0) failed");
196 }
197 cleanup();
198
199 tst_exit();
200 }
201
202 /*
203 * setup() - performs all ONE TIME setup for this test.
204 */
setup(void)205 void setup(void)
206 {
207
208 tst_sig(FORK, DEF_HANDLER, cleanup);
209
210 TEST_PAUSE;
211 }
212
213 /*
214 * cleanup() - performs all ONE TIME cleanup for this test at
215 * completion or premature exit.
216 */
cleanup(void)217 void cleanup(void)
218 {
219 }
220
c1func(void)221 void c1func(void)
222 {
223 if (close(fildes[0]) == -1)
224 tst_resm(TWARN, "Could not close fildes[0] - errno %d", errno);
225 while (1)
226 if (write(fildes[1], "bbbbbbbbbbbbbbbbbbbbbbbbb", 25) == -1)
227 tst_resm(TBROK | TERRNO, "[child 1] pipe write failed");
228 }
229
c2func(void)230 void c2func(void)
231 {
232 if (close(fildes[0]) == -1)
233 tst_resm(TWARN, "Could not close fildes[0] - errno %d", errno);
234 while (1)
235 if (write(fildes[1], "AAAAAAAAAAAAAAAAAAAAAAAAA", 25) == -1)
236 tst_resm(TBROK | TERRNO, "[child 2] pipe write failed");
237 }
238
alarmfunc(int sig)239 void alarmfunc(int sig)
240 {
241 /* for some reason tst_brkm doesn't seem to work in a signal handler */
242 tst_brkm(TFAIL, cleanup, "one or more children did't die in 60 second "
243 "time limit");
244 }
245