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  * MPR An implementation may permit accesses other than those specified by prot;
10  * however, if the Memory Protection option is supported, the implementation
11  * shall not permit a write to succeed where PROT_WRITE has not been set or
12  * shall not permit any access where PROT_NONE alone has been set.
13  * The implementation shall support at least the following values of prot:
14  * PROT_NONE, PROT_READ, PROT_WRITE, and the bitwise-inclusive OR of PROT_READ
15  * and PROT_WRITE.
16  *
17  * Test Steps:
18  *
19  * If Memory Protection option is supported:
20  * 1. Spawn a child process.
21  * 2. The child process mmap a memory region setting prot as PROT_READ.
22  * 3. Try to write the mapped memory.
23  * 4. If the writing triger SIGSEGV, the PASS.
24  *
25  * Please refer to IEEE_1003.1-2001. 2.8.3.3 Memory Protection.
26  */
27 
28 #include <sys/mman.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/wait.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <signal.h>
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <string.h>
38 #include <unistd.h>
39 
40 #include "posixtest.h"
41 #include "tempfile.h"
42 
main(void)43 int main(void)
44 {
45 #ifdef _POSIX_MEMORY_PROTECTION
46 	char tmpfname[PATH_MAX];
47 	void *pa;
48 	size_t size = 1024;
49 	int fd;
50 
51 	pid_t child;
52 	int status;
53 	int sig_num;
54 
55 	PTS_GET_TMP_FILENAME(tmpfname, "pts_mmap_6_1");
56 	unlink(tmpfname);
57 	fd = open(tmpfname, O_CREAT | O_RDWR | O_EXCL, S_IRUSR | S_IWUSR);
58 	if (fd == -1) {
59 		printf("Error at open(): %s\n", strerror(errno));
60 		return PTS_UNRESOLVED;
61 	}
62 	unlink(tmpfname);
63 
64 	child = fork();
65 
66 	switch (child) {
67 	case 0:
68 		if (ftruncate(fd, size) == -1) {
69 			printf("Error at ftruncate(): %s\n", strerror(errno));
70 			return PTS_UNRESOLVED;
71 		}
72 
73 		pa = mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0);
74 		if (pa == MAP_FAILED) {
75 			printf("Error at mmap: %s\n", strerror(errno));
76 			return PTS_FAIL;
77 		}
78 
79 		*(char *)pa = 'b';
80 		return 0;
81 		break;
82 	case -1:
83 		printf("Error at fork(): %s\n", strerror(errno));
84 		return PTS_UNRESOLVED;
85 		break;
86 	default:
87 		break;
88 	}
89 
90 	waitpid(child, &status, WUNTRACED);
91 	close(fd);
92 
93 	if (WIFSIGNALED(status)) {
94 		sig_num = WTERMSIG(status);
95 		printf("Child process terminated by signal %d\n", sig_num);
96 		if (sig_num == SIGSEGV) {
97 			printf("Got SIGSEGV when writing to the mapped memory, "
98 			       "without setting PROT_WRITE\n" "Test PASSED\n");
99 			return PTS_PASS;
100 		}
101 	}
102 
103 	if (WIFEXITED(status)) {
104 		if (WEXITSTATUS(status) == 0) {
105 			printf
106 			    ("Did not got SIGSEGV when writing to the mapped memory,"
107 			     " without setting PROT_WRITE\n" "Test FAILED\n");
108 			return PTS_FAIL;
109 		}
110 	}
111 
112 	printf("Test Unresolved\n");
113 	return PTS_UNRESOLVED;
114 #else
115 	printf("Test Unsupported, _POSIX_MEMORY_PROTECTION not defined\n");
116 	return PTS_UNSUPPORTED;
117 #endif
118 }
119