Home | History | Annotate | Download | only in timers 
      1 /* Time bounds setting test
      2  *		by: john stultz (johnstul (at) 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 #ifdef KTEST
     31 #include "../kselftest.h"
     32 #else
     33 static inline int ksft_exit_pass(void)
     34 {
     35 	exit(0);
     36 }
     37 static inline int ksft_exit_fail(void)
     38 {
     39 	exit(1);
     40 }
     41 #endif
     42 
     43 #define NSEC_PER_SEC 1000000000LL
     44 
     45 #define KTIME_MAX	((long long)~((unsigned long long)1 << 63))
     46 #define KTIME_SEC_MAX	(KTIME_MAX / NSEC_PER_SEC)
     47 
     48 #define YEAR_1901 (-0x7fffffffL)
     49 #define YEAR_1970 1
     50 #define YEAR_2038 0x7fffffffL			/*overflows 32bit time_t */
     51 #define YEAR_2262 KTIME_SEC_MAX			/*overflows 64bit ktime_t */
     52 #define YEAR_MAX  ((long long)((1ULL<<63)-1))	/*overflows 64bit time_t */
     53 
     54 int is32bits(void)
     55 {
     56 	return (sizeof(long) == 4);
     57 }
     58 
     59 int settime(long long time)
     60 {
     61 	struct timeval now;
     62 	int ret;
     63 
     64 	now.tv_sec = (time_t)time;
     65 	now.tv_usec  = 0;
     66 
     67 	ret = settimeofday(&now, NULL);
     68 
     69 	printf("Setting time to 0x%lx: %d\n", (long)time, ret);
     70 	return ret;
     71 }
     72 
     73 int do_tests(void)
     74 {
     75 	int ret;
     76 
     77 	ret = system("date");
     78 	ret = system("./inconsistency-check -c 0 -t 20");
     79 	ret |= system("./nanosleep");
     80 	ret |= system("./nsleep-lat");
     81 	return ret;
     82 
     83 }
     84 
     85 int main(int argc, char *argv[])
     86 {
     87 	int ret = 0;
     88 	int opt, dangerous = 0;
     89 	time_t start;
     90 
     91 	/* Process arguments */
     92 	while ((opt = getopt(argc, argv, "d")) != -1) {
     93 		switch (opt) {
     94 		case 'd':
     95 			dangerous = 1;
     96 		}
     97 	}
     98 
     99 	start = time(0);
    100 
    101 	/* First test that crazy values don't work */
    102 	if (!settime(YEAR_1901)) {
    103 		ret = -1;
    104 		goto out;
    105 	}
    106 	if (!settime(YEAR_MAX)) {
    107 		ret = -1;
    108 		goto out;
    109 	}
    110 	if (!is32bits() && !settime(YEAR_2262)) {
    111 		ret = -1;
    112 		goto out;
    113 	}
    114 
    115 	/* Now test behavior near edges */
    116 	settime(YEAR_1970);
    117 	ret = do_tests();
    118 	if (ret)
    119 		goto out;
    120 
    121 	settime(YEAR_2038 - 600);
    122 	ret = do_tests();
    123 	if (ret)
    124 		goto out;
    125 
    126 	/* The rest of the tests can blowup on 32bit systems */
    127 	if (is32bits() && !dangerous)
    128 		goto out;
    129 	/* Test rollover behavior 32bit edge */
    130 	settime(YEAR_2038 - 10);
    131 	ret = do_tests();
    132 	if (ret)
    133 		goto out;
    134 
    135 	settime(YEAR_2262 - 600);
    136 	ret = do_tests();
    137 
    138 out:
    139 	/* restore clock */
    140 	settime(start);
    141 	if (ret)
    142 		return ksft_exit_fail();
    143 	return ksft_exit_pass();
    144 }
    145