1 /* ADJ_FREQ Skew change 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 cranks the ADJ_FREQ knob and
7  *  then uses other tests to detect problems. Thus this test requires
8  *  that the raw_skew, inconsistency-check and nanosleep tests be
9  *  present in the same directory it is run from.
10  *
11  *  To build:
12  *	$ gcc change_skew.c -o change_skew -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 
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <sys/time.h>
29 #include <sys/timex.h>
30 #include <time.h>
31 #include "../kselftest.h"
32 
33 #define NSEC_PER_SEC 1000000000LL
34 
35 
36 int change_skew_test(int ppm)
37 {
38 	struct timex tx;
39 	int ret;
40 
41 	tx.modes = ADJ_FREQUENCY;
42 	tx.freq = ppm << 16;
43 
44 	ret = adjtimex(&tx);
45 	if (ret < 0) {
46 		printf("Error adjusting freq\n");
47 		return ret;
48 	}
49 
50 	ret = system("./raw_skew");
51 	ret |= system("./inconsistency-check");
52 	ret |= system("./nanosleep");
53 
54 	return ret;
55 }
56 
57 
58 int main(int argc, char **argv)
59 {
60 	struct timex tx;
61 	int i, ret;
62 
63 	int ppm[5] = {0, 250, 500, -250, -500};
64 
65 	/* Kill ntpd */
66 	ret = system("killall -9 ntpd");
67 
68 	/* Make sure there's no offset adjustment going on */
69 	tx.modes = ADJ_OFFSET;
70 	tx.offset = 0;
71 	ret = adjtimex(&tx);
72 
73 	if (ret < 0) {
74 		printf("Maybe you're not running as root?\n");
75 		return -1;
76 	}
77 
78 	for (i = 0; i < 5; i++) {
79 		printf("Using %i ppm adjustment\n", ppm[i]);
80 		ret = change_skew_test(ppm[i]);
81 		if (ret)
82 			break;
83 	}
84 
85 	/* Set things back */
86 	tx.modes = ADJ_FREQUENCY;
87 	tx.offset = 0;
88 	adjtimex(&tx);
89 
90 	if (ret) {
91 		printf("[FAIL]");
92 		return ksft_exit_fail();
93 	}
94 	printf("[OK]");
95 	return ksft_exit_pass();
96 }
97