xref: /freebsd/tests/sys/kern/pipe/pipe_fstat_bug_test.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*
2 Copyright (C) 2004 Michael J. Silbersack. All rights reserved.
3 
4 Redistribution and use in source and binary forms, with or without
5 modification, are permitted provided that the following conditions
6 are met:
7 1. Redistributions of source code must retain the above copyright
8    notice, this list of conditions and the following disclaimer.
9 2. Redistributions in binary form must reproduce the above copyright
10    notice, this list of conditions and the following disclaimer in the
11    documentation and/or other materials provided with the distribution.
12 
13 THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 SUCH DAMAGE.
24 */
25 
26 #include <sys/types.h>
27 #include <sys/stat.h>
28 #include <sys/wait.h>
29 #include <sys/event.h>
30 #include <assert.h>
31 #include <err.h>
32 #include <errno.h>
33 #include <inttypes.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <unistd.h>
37 
38 /*
39  * The goal of this program is to see if fstat reports the correct
40  * data count for a pipe.  Prior to revision 1.172 of sys_pipe.c,
41  * 0 would be returned once the pipe entered direct write mode.
42  *
43  * Linux (2.6) always returns zero, so it's not a valuable platform
44  * for comparison.
45  */
46 
47 int
48 main(void)
49 {
50 	char buffer[32768], buffer2[32768], go[] = "go", go2[] = "go2";
51 	int desc[2], ipc_coord[2];
52 	struct kevent event, ke;
53 	ssize_t error;
54 	int successes = 0;
55 	struct stat status;
56 	pid_t new_pid;
57 	int kq;
58 
59 	error = pipe(desc);
60 	if (error == -1)
61 		err(1, "Couldn't allocate data pipe");
62 
63 	error = pipe(ipc_coord);
64 	if (error == -1)
65 		err(1, "Couldn't allocate IPC coordination pipe");
66 
67 	new_pid = fork();
68 	assert(new_pid != -1);
69 
70 	close(new_pid == 0 ? desc[0] : desc[1]);
71 
72 #define	SYNC_R(i, _buf) do {	\
73 	int _error = errno; \
74 	warnx("%d: waiting for synchronization", __LINE__); \
75 	if (read(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
76 		err(1, "failed to synchronize (%s)", (i == 0 ? "parent" : "child")); \
77 	errno = _error; \
78 	} while(0)
79 
80 #define	SYNC_W(i, _buf) do {	\
81 	int _error = errno; \
82 	warnx("%d: sending synchronization", __LINE__); \
83 	if (write(ipc_coord[i], &_buf, sizeof(_buf)) != sizeof(_buf)) \
84 		err(1, "failed to synchronize (%s)", (i == 0 ? "child" : "parent")); \
85 	errno = _error; \
86 	} while(0)
87 
88 #define	WRITE(s) do { 							\
89 	ssize_t _size; 							\
90 	if ((_size = write(desc[1], &buffer, s)) != s)			\
91 		warn("short write; wrote %zd, expected %d", _size, s);	\
92 	} while(0)
93 
94 	if (new_pid == 0) {
95 
96 		SYNC_R(0, go);
97 		WRITE(145);
98 		SYNC_W(0, go2);
99 
100 		SYNC_R(0, go);
101 		WRITE(2048);
102 		SYNC_W(0, go2);
103 
104 		SYNC_R(0, go);
105 		WRITE(4096);
106 		SYNC_W(0, go2);
107 
108 		SYNC_R(0, go);
109 		WRITE(8191);
110 		SYNC_W(0, go2);
111 
112 		SYNC_R(0, go);
113 		SYNC_W(0, go2); /* XXX: why is this required? */
114 		WRITE(8192);
115 		SYNC_W(0, go2);
116 
117 		close(ipc_coord[0]);
118 		close(ipc_coord[1]);
119 
120 		_exit(0);
121 	}
122 
123 	kq = kqueue();
124 	if (kq == -1)
125 		_exit(1);
126 
127 	EV_SET(&ke, desc[0], EVFILT_READ, EV_ADD, 0, 0, NULL);
128 
129 	/* Attach event to the kqueue. */
130 	if (kevent(kq, &ke, 1, NULL, 0, NULL) != 0)
131 		_exit(2);
132 
133 	while (successes < 5) {
134 		SYNC_W(1, go);
135 		SYNC_R(1, go2);
136 
137 		/* Ensure data is available to read */
138 		if (kevent(kq, NULL, 0, &event, 1, NULL) != 1)
139 			_exit(3);
140 
141 		fstat(desc[0], &status);
142 		error = read(desc[0], &buffer2, sizeof(buffer2));
143 
144 		if (status.st_size != error)
145 			err(1, "FAILURE: stat size %jd read size %zd",
146 			    (intmax_t)status.st_size, error);
147 		if (error > 0) {
148 			printf("SUCCESS at stat size %jd read size %zd\n",
149 			    (intmax_t)status.st_size, error);
150 			successes++;
151 		}
152 	}
153 
154 	exit(0);
155 }
156