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/... with minimum address. */ |
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 | |
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 | |
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 | |
47 | int main(void) |
48 | { |
49 | const int PAGE_SIZE = sysconf(_SC_PAGESIZE); |
50 | /* |
51 | * va_max must be enough bigger than vm.mmap_min_addr, which is |
52 | * 64KB/32KB by default. (depends on CONFIG_LSM_MMAP_MIN_ADDR) |
53 | */ |
54 | const unsigned long va_max = 1UL << 20; |
55 | unsigned long va; |
56 | void *p; |
57 | int fd; |
58 | unsigned long a, b; |
59 | |
60 | fd = open("/dev/zero" , O_RDONLY); |
61 | if (fd == -1) |
62 | return 1; |
63 | |
64 | for (va = 0; va < va_max; va += PAGE_SIZE) { |
65 | p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0); |
66 | if (p == (void *)va) |
67 | break; |
68 | } |
69 | if (va == va_max) { |
70 | fprintf(stderr, "error: mmap doesn't like you\n" ); |
71 | return 1; |
72 | } |
73 | |
74 | a = (unsigned long)p; |
75 | b = (unsigned long)p + PAGE_SIZE; |
76 | |
77 | pass(fmt: "/proc/self/map_files/%lx-%lx" , a, b); |
78 | fail(fmt: "/proc/self/map_files/ %lx-%lx" , a, b); |
79 | fail(fmt: "/proc/self/map_files/%lx -%lx" , a, b); |
80 | fail(fmt: "/proc/self/map_files/%lx- %lx" , a, b); |
81 | fail(fmt: "/proc/self/map_files/%lx-%lx " , a, b); |
82 | fail(fmt: "/proc/self/map_files/0%lx-%lx" , a, b); |
83 | fail(fmt: "/proc/self/map_files/%lx-0%lx" , a, b); |
84 | if (sizeof(long) == 4) { |
85 | fail(fmt: "/proc/self/map_files/100000000%lx-%lx" , a, b); |
86 | fail(fmt: "/proc/self/map_files/%lx-100000000%lx" , a, b); |
87 | } else if (sizeof(long) == 8) { |
88 | fail(fmt: "/proc/self/map_files/10000000000000000%lx-%lx" , a, b); |
89 | fail(fmt: "/proc/self/map_files/%lx-10000000000000000%lx" , a, b); |
90 | } else |
91 | return 1; |
92 | |
93 | return 0; |
94 | } |
95 | |