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
change_skew_test(int ppm)33 int change_skew_test(int ppm)
34 {
35 struct timex tx;
36 int ret;
37
38 tx.modes = ADJ_FREQUENCY;
39 tx.freq = ppm << 16;
40
41 ret = adjtimex(&tx);
42 if (ret < 0) {
43 printf("Error adjusting freq\n");
44 return ret;
45 }
46
47 ret = system("./raw_skew");
48 ret |= system("./inconsistency-check");
49 ret |= system("./nanosleep");
50
51 return ret;
52 }
53
54
main(int argc,char ** argv)55 int main(int argc, char **argv)
56 {
57 struct timex tx;
58 int i, ret;
59
60 int ppm[5] = {0, 250, 500, -250, -500};
61
62 /* Kill ntpd */
63 ret = system("killall -9 ntpd");
64
65 /* Make sure there's no offset adjustment going on */
66 tx.modes = ADJ_OFFSET;
67 tx.offset = 0;
68 ret = adjtimex(&tx);
69
70 if (ret < 0) {
71 printf("Maybe you're not running as root?\n");
72 return -1;
73 }
74
75 for (i = 0; i < 5; i++) {
76 printf("Using %i ppm adjustment\n", ppm[i]);
77 ret = change_skew_test(ppm[i]);
78 if (ret)
79 break;
80 }
81
82 /* Set things back */
83 tx.modes = ADJ_FREQUENCY;
84 tx.offset = 0;
85 adjtimex(&tx);
86
87 if (ret) {
88 printf("[FAIL]");
89 ksft_exit_fail();
90 }
91 printf("[OK]");
92 ksft_exit_pass();
93 }
94