1 /*
2 * Copyright (c) 2002, Intel Corporation. All rights reserved.
3 * Copyright (c) 2012, Cyril Hrubis <chrubis@suse.cz>
4 *
5 * This file is licensed under the GPL license. For the full content
6 * of this license, see the COPYING file at the top level of this
7 * source tree.
8 *
9 * Implementation performs mapping operations over whole pages.
10 * Thus, while the argument len
11 * need not meet a size or alignment constraint,
12 * the implementation shall include, in any mapping
13 * operation, any partial page specified by the range [pa,pa+len).
14 * The system shall always zero-fill any partial page at the end of an object.
15 * Further, the system shall never write out any modified portions of
16 * the last page of an object which are beyond its end.
17 *
18 * Test Steps:
19 * 1. Create a process, in this process:
20 * a. map a file with size of 1/2 * page_size,
21 * set len = 1/2 * page_size
22 * b. Read the partial page beyond the object size.
23 * Make sure the partial page is zero-filled;
24 * c. Modify a byte in the partial page, then un-map the and close the
25 * file descriptor.
26 * 2. Wait for the child proces to exit, then
27 * Map the file again,
28 * read the byte from the position modified at step 1-c and check.
29 */
30
31
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <unistd.h>
35 #include <sys/mman.h>
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 #include <sys/wait.h>
39 #include <fcntl.h>
40 #include <string.h>
41 #include <errno.h>
42 #ifdef __linux__
43 #include <sys/vfs.h>
44 #endif
45 #include "posixtest.h"
46
47 #define TYPE_TMPFS_MAGIC 0x01021994
48
main(void)49 int main(void)
50 {
51 char tmpfname[256];
52 long page_size;
53
54 char *pa;
55 size_t len;
56 int fd;
57
58 pid_t child;
59 int i, exit_val;
60
61 page_size = sysconf(_SC_PAGE_SIZE);
62
63 /* mmap will create a partial page */
64 len = page_size / 2;
65
66 #ifdef __linux__
67 struct statfs buf;
68
69 if (statfs("/tmp", &buf)) {
70 printf("Error at statfs(): %s\n", strerror(errno));
71 return PTS_UNRESOLVED;
72 }
73
74 if (buf.f_type == TYPE_TMPFS_MAGIC) {
75 printf("From mmap(2) manpage, skip known bug on tmpfs\n");
76 return PTS_UNTESTED;
77 }
78 #endif
79
80 snprintf(tmpfname, sizeof(tmpfname), "/tmp/pts_mmap_11_5_%d", getpid());
81 child = fork();
82 switch (child) {
83 case 0:
84 /* Create shared object */
85 unlink(tmpfname);
86 fd = open(tmpfname, O_CREAT | O_RDWR | O_EXCL,
87 S_IRUSR | S_IWUSR);
88 if (fd == -1) {
89 printf("Error at open(): %s\n", strerror(errno));
90 return PTS_UNRESOLVED;
91 }
92 if (ftruncate(fd, len) == -1) {
93 printf("Error at ftruncate(): %s\n", strerror(errno));
94 return PTS_UNRESOLVED;
95 }
96
97 pa = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
98 if (pa == MAP_FAILED) {
99 printf("Error at mmap(): %s\n", strerror(errno));
100 return PTS_FAIL;
101 }
102
103 /* Check the patial page is ZERO filled */
104 for (i = len; i < page_size; i++)
105 if (pa[i] != 0) {
106 printf("Test FAILED: The partial page at the "
107 "end of an object is not zero-filled\n");
108 return PTS_FAIL;
109 }
110
111 /* Write the partial page */
112 pa[len + 1] = 'b';
113 msync(pa, len, MS_SYNC);
114 munmap(pa, len);
115 close(fd);
116 return PTS_PASS;
117 case -1:
118 printf("Error at fork(): %s\n", strerror(errno));
119 return PTS_UNRESOLVED;
120 default:
121 break;
122 }
123
124 wait(&exit_val);
125 if (!(WIFEXITED(exit_val) && (WEXITSTATUS(exit_val) == PTS_PASS))) {
126 unlink(tmpfname);
127
128 if (WIFEXITED(exit_val))
129 return WEXITSTATUS(exit_val);
130
131 printf("Child exited abnormally\n");
132 return PTS_UNRESOLVED;
133 }
134
135 fd = open(tmpfname, O_RDWR, 0);
136 unlink(tmpfname);
137
138 pa = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
139 if (pa == MAP_FAILED) {
140 printf("Error at 2nd mmap(): %s\n", strerror(errno));
141 return PTS_FAIL;
142 }
143
144 if (pa[len + 1] == 'b') {
145 printf("Test FAILED: Modification of the partial page "
146 "at the end of an object is written out\n");
147 return PTS_FAIL;
148 }
149 close(fd);
150 munmap(pa, len);
151
152 printf("Test PASSED\n");
153 return PTS_PASS;
154 }
155