1 /*
2  * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 /* Test readlink /proc/self/map_files/... */
17 #include <errno.h>
18 #include <sys/types.h>
19 #include <sys/stat.h>
20 #include <fcntl.h>
21 #include <stdio.h>
22 #include <unistd.h>
23 #include <sys/mman.h>
24 #include <stdlib.h>
25 
pass(const char * fmt,unsigned long a,unsigned long b)26 static void pass(const char *fmt, unsigned long a, unsigned long b)
27 {
28 	char name[64];
29 	char buf[64];
30 
31 	snprintf(name, sizeof(name), fmt, a, b);
32 	if (readlink(name, buf, sizeof(buf)) == -1)
33 		exit(1);
34 }
35 
fail(const char * fmt,unsigned long a,unsigned long b)36 static void fail(const char *fmt, unsigned long a, unsigned long b)
37 {
38 	char name[64];
39 	char buf[64];
40 
41 	snprintf(name, sizeof(name), fmt, a, b);
42 	if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
43 		return;
44 	exit(1);
45 }
46 
main(void)47 int main(void)
48 {
49 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
50 	void *p;
51 	int fd;
52 	unsigned long a, b;
53 
54 	fd = open("/dev/zero", O_RDONLY);
55 	if (fd == -1)
56 		return 1;
57 
58 	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE, fd, 0);
59 	if (p == MAP_FAILED)
60 		return 1;
61 
62 	a = (unsigned long)p;
63 	b = (unsigned long)p + PAGE_SIZE;
64 
65 	pass("/proc/self/map_files/%lx-%lx", a, b);
66 	fail("/proc/self/map_files/ %lx-%lx", a, b);
67 	fail("/proc/self/map_files/%lx -%lx", a, b);
68 	fail("/proc/self/map_files/%lx- %lx", a, b);
69 	fail("/proc/self/map_files/%lx-%lx ", a, b);
70 	fail("/proc/self/map_files/0%lx-%lx", a, b);
71 	fail("/proc/self/map_files/%lx-0%lx", a, b);
72 	if (sizeof(long) == 4) {
73 		fail("/proc/self/map_files/100000000%lx-%lx", a, b);
74 		fail("/proc/self/map_files/%lx-100000000%lx", a, b);
75 	} else if (sizeof(long) == 8) {
76 		fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
77 		fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
78 	} else
79 		return 1;
80 
81 	return 0;
82 }
83