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 shared memory object 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 read the file using read()
27 * and check that change wasn't written.
28 */
29
30 #define _XOPEN_SOURCE 600
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 #include "posixtest.h"
43
main(void)44 int main(void)
45 {
46 char tmpfname[256];
47 long page_size;
48
49 char *pa, ch;
50 ssize_t len;
51 int fd;
52
53 pid_t child;
54 int i, exit_val, ret, size;
55
56 page_size = sysconf(_SC_PAGE_SIZE);
57
58 /* mmap will create a partial page */
59 len = page_size / 2;
60
61 snprintf(tmpfname, sizeof(tmpfname), "pts_mmap_11_5_%d", getpid());
62 child = fork();
63 switch (child) {
64 case 0:
65 /* Create shared object */
66 shm_unlink(tmpfname);
67 fd = shm_open(tmpfname, O_RDWR | O_CREAT | O_EXCL,
68 S_IRUSR | S_IWUSR);
69 if (fd == -1) {
70 printf("Error at shm_open(): %s\n", strerror(errno));
71 return PTS_UNRESOLVED;
72 }
73 if (ftruncate(fd, len) == -1) {
74 printf("Error at ftruncate(): %s\n", strerror(errno));
75 return PTS_UNRESOLVED;
76 }
77
78 pa = mmap(NULL, len, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
79 if (pa == MAP_FAILED) {
80 printf("Error at mmap(): %s\n", strerror(errno));
81 return PTS_FAIL;
82 }
83
84 /* Check the patial page is ZERO filled */
85 for (i = len; i < page_size; i++)
86 if (pa[i] != 0) {
87 printf("Test FAILED: The partial page at the "
88 "end of an object is not zero-filled\n");
89 return PTS_FAIL;
90 }
91
92 /* Write the partial page */
93 pa[len + 1] = 'b';
94 munmap(pa, len);
95 close(fd);
96 return PTS_PASS;
97 case -1:
98 printf("Error at fork(): %s\n", strerror(errno));
99 return PTS_UNRESOLVED;
100 default:
101 break;
102 }
103
104 wait(&exit_val);
105 if (!(WIFEXITED(exit_val) && (WEXITSTATUS(exit_val) == PTS_PASS))) {
106 unlink(tmpfname);
107
108 if (WIFEXITED(exit_val))
109 return WEXITSTATUS(exit_val);
110
111 printf("Child exited abnormally\n");
112 return PTS_UNRESOLVED;
113 }
114
115 fd = shm_open(tmpfname, O_RDWR, 0);
116 shm_unlink(tmpfname);
117
118 size = 0;
119
120 while ((ret = read(fd, &ch, 1)) == 1) {
121
122 if (ch != 0) {
123 printf("File is not zeroed\n");
124 return PTS_FAIL;
125 }
126
127 size += ret;
128 }
129
130 if (ret == -1) {
131 printf("Error at read(): %s\n", strerror(errno));
132 return PTS_UNRESOLVED;
133 }
134
135 if (size != len) {
136 printf("File has wrong size\n");
137 return PTS_UNRESOLVED;
138 }
139
140 close(fd);
141
142 printf("Test PASSED\n");
143 return PTS_PASS;
144 }
145