1/* Time bounds setting test
2 * by: john stultz (johnstul@us.ibm.com)
3 * (C) Copyright IBM 2012
4 * Licensed under the GPLv2
5 *
6 * NOTE: This is a meta-test which sets the time to edge cases then
7 * uses other tests to detect problems. Thus this test requires that
8 * the inconsistency-check and nanosleep tests be present in the same
9 * directory it is run from.
10 *
11 * To build:
12 * $ gcc set-2038.c -o set-2038 -lrt
13 *
14 * This program is free software: you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation, either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 */
24
25#include <stdio.h>
26#include <stdlib.h>
27#include <unistd.h>
28#include <time.h>
29#include <sys/time.h>
30#include "../kselftest.h"
31
32#define NSEC_PER_SEC 1000000000LL
33
34#define KTIME_MAX ((long long)~((unsigned long long)1 << 63))
35#define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
36
37#define YEAR_1901 (-0x7fffffffL)
38#define YEAR_1970 1
39#define YEAR_2038 0x7fffffffL /*overflows 32bit time_t */
40#define YEAR_2262 KTIME_SEC_MAX /*overflows 64bit ktime_t */
41#define YEAR_MAX ((long long)((1ULL<<63)-1)) /*overflows 64bit time_t */
42
43int is32bits(void)
44{
45 return (sizeof(long) == 4);
46}
47
48int settime(long long time)
49{
50 struct timeval now;
51 int ret;
52
53 now.tv_sec = (time_t)time;
54 now.tv_usec = 0;
55
56 ret = settimeofday(&now, NULL);
57
58 printf("Setting time to 0x%lx: %d\n", (long)time, ret);
59 return ret;
60}
61
62int do_tests(void)
63{
64 int ret;
65
66 ret = system("date");
67 ret = system("./inconsistency-check -c 0 -t 20");
68 ret |= system("./nanosleep");
69 ret |= system("./nsleep-lat");
70 return ret;
71
72}
73
74int main(int argc, char *argv[])
75{
76 int ret = 0;
77 int opt, dangerous = 0;
78 time_t start;
79
80 /* Process arguments */
81 while ((opt = getopt(argc, argv, "d")) != -1) {
82 switch (opt) {
83 case 'd':
84 dangerous = 1;
85 }
86 }
87
88 start = time(0);
89
90 /* First test that crazy values don't work */
91 if (!settime(YEAR_1901)) {
92 ret = -1;
93 goto out;
94 }
95 if (!settime(YEAR_MAX)) {
96 ret = -1;
97 goto out;
98 }
99 if (!is32bits() && !settime(YEAR_2262)) {
100 ret = -1;
101 goto out;
102 }
103
104 /* Now test behavior near edges */
105 settime(YEAR_1970);
106 ret = do_tests();
107 if (ret)
108 goto out;
109
110 settime(YEAR_2038 - 600);
111 ret = do_tests();
112 if (ret)
113 goto out;
114
115 /* The rest of the tests can blowup on 32bit systems */
116 if (is32bits() && !dangerous)
117 goto out;
118 /* Test rollover behavior 32bit edge */
119 settime(YEAR_2038 - 10);
120 ret = do_tests();
121 if (ret)
122 goto out;
123
124 settime(YEAR_2262 - 600);
125 ret = do_tests();
126
127out:
128 /* restore clock */
129 settime(start);
130 if (ret)
131 return ksft_exit_fail();
132 return ksft_exit_pass();
133}
134

source code of linux/tools/testing/selftests/timers/set-2038.c