1 /*
2  *
3  *   Copyright (c) International Business Machines  Corp., 2001
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  *	write03.c
23  *
24  * DESCRIPTION
25  *	Testcase to check that write(2) doesn't corrupt a file when it fails
26  *
27  * ALGORITHM
28  *	Create a file for writing, write 100 bytes to it. Then make write(2)
29  *	fail with some erroneous parameter, close the fd. Then reopen the
30  *	file in RDONLY mode, and read the contents of the file. Compare the
31  *	buffers, to see whether they are same.
32  *
33  * USAGE:  <for command-line>
34  *      write03 [-c n] [-e] [-i n] [-I x] [-P x] [-t]
35  *      where,  -c n : Run n copies concurrently.
36  *              -e   : Turn on errno logging.
37  *              -i n : Execute test n times.
38  *              -I x : Execute test for x seconds.
39  *              -P x : Pause for x seconds between iterations.
40  *              -t   : Turn on syscall timing.
41  *
42  * History
43  *	07/2001 John George
44  *		-Ported
45  *
46  * Restrictions
47  *	NONE
48  */
49 
50 #include <unistd.h>
51 #include <string.h>
52 #include <fcntl.h>
53 #include <errno.h>
54 #include "test.h"
55 #include <sys/mman.h>
56 
57 char *TCID = "write03";
58 int TST_TOTAL = 1;
59 
60 char *bad_addr = 0;
61 
62 void setup(void);
63 void cleanup(void);
64 
65 char filename[100];
66 
67 #if !defined(UCLINUX)
68 
main(int argc,char ** argv)69 int main(int argc, char **argv)
70 {
71 	int lc;
72 
73 	char wbuf[BUFSIZ], rbuf[BUFSIZ];
74 	int fd;
75 
76 	tst_parse_opts(argc, argv, NULL, NULL);
77 
78 	/* global setup */
79 	setup();
80 
81 	/* The following loop checks looping state if -i option given */
82 	for (lc = 0; TEST_LOOPING(lc); lc++) {
83 
84 		/* reset tst_count in case we are looping */
85 		tst_count = 0;
86 
87 //block1:
88 		tst_resm(TINFO, "Enter Block 1: test to check if write "
89 			 "corrupts the file when write fails");
90 
91 		fd = creat(filename, 0644);
92 		if (fd < 0) {
93 			tst_resm(TBROK, "creating a new file failed");
94 			cleanup();
95 		}
96 
97 		(void)memset(wbuf, '0', 100);
98 
99 		if (write(fd, wbuf, 100) == -1) {
100 			tst_resm(TFAIL, "failed to write to %s", filename);
101 			cleanup();
102 		}
103 
104 		if (write(fd, bad_addr, 100) != -1) {
105 			tst_resm(TFAIL, "write(2) failed to fail");
106 			cleanup();
107 		}
108 		close(fd);
109 
110 		if ((fd = open(filename, O_RDONLY)) == -1) {
111 			tst_resm(TBROK, "open(2) failed, errno: %d", errno);
112 			cleanup();
113 		}
114 
115 		if (read(fd, rbuf, 100) == -1) {
116 			tst_resm(TBROK, "read(2) failed, errno: %d", errno);
117 			cleanup();
118 		}
119 
120 		if (memcmp(wbuf, rbuf, 100) == 0) {
121 			tst_resm(TPASS, "failure of write(2) didnot corrupt "
122 				 "the file");
123 		} else {
124 			tst_resm(TFAIL, "failure of write(2) corrupted the "
125 				 "file");
126 		}
127 		tst_resm(TINFO, "Exit block 1");
128 		close(fd);
129 	}
130 	cleanup();
131 	tst_exit();
132 }
133 
134 #else
135 
main(void)136 int main(void)
137 {
138 	tst_resm(TINFO, "test is not available on uClinux");
139 	tst_exit();
140 }
141 
142 #endif /* if !defined(UCLINUX) */
143 
144 /*
145  * setup() - performs all ONE TIME setup for this test
146  */
setup(void)147 void setup(void)
148 {
149 
150 	tst_sig(FORK, DEF_HANDLER, cleanup);
151 
152 	/* Pause if that option was specified
153 	 * TEST_PAUSE contains the code to fork the test with the -i option.
154 	 * You want to make sure you do this before you create your temporary
155 	 * directory.
156 	 */
157 	TEST_PAUSE;
158 
159 	/* Create a unique temporary directory and chdir() to it. */
160 	tst_tmpdir();
161 
162 	sprintf(filename, "./write03.%d", getpid());
163 
164 	bad_addr = mmap(0, 1, PROT_NONE,
165 			MAP_PRIVATE_EXCEPT_UCLINUX | MAP_ANONYMOUS, 0, 0);
166 	if (bad_addr == MAP_FAILED) {
167 		printf("mmap failed\n");
168 	}
169 
170 }
171 
172 /*
173  * cleanup() - performs all ONE TIME cleanup for this test at
174  *		completion or premature exit
175  */
cleanup(void)176 void cleanup(void)
177 {
178 
179 	unlink(filename);
180 	tst_rmdir();
181 
182 }
183