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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 #ifdef KTEST
32 #include "../kselftest.h"
33 #else
ksft_exit_pass(void)34 static inline int ksft_exit_pass(void)
35 {
36 	exit(0);
37 }
ksft_exit_fail(void)38 static inline int ksft_exit_fail(void)
39 {
40 	exit(1);
41 }
42 #endif
43 
44 #define NSEC_PER_SEC 1000000000LL
45 
46 
change_skew_test(int ppm)47 int change_skew_test(int ppm)
48 {
49 	struct timex tx;
50 	int ret;
51 
52 	tx.modes = ADJ_FREQUENCY;
53 	tx.freq = ppm << 16;
54 
55 	ret = adjtimex(&tx);
56 	if (ret < 0) {
57 		printf("Error adjusting freq\n");
58 		return ret;
59 	}
60 
61 	ret = system("./raw_skew");
62 	ret |= system("./inconsistency-check");
63 	ret |= system("./nanosleep");
64 
65 	return ret;
66 }
67 
68 
main(int argv,char ** argc)69 int main(int argv, char **argc)
70 {
71 	struct timex tx;
72 	int i, ret;
73 
74 	int ppm[5] = {0, 250, 500, -250, -500};
75 
76 	/* Kill ntpd */
77 	ret = system("killall -9 ntpd");
78 
79 	/* Make sure there's no offset adjustment going on */
80 	tx.modes = ADJ_OFFSET;
81 	tx.offset = 0;
82 	ret = adjtimex(&tx);
83 
84 	if (ret < 0) {
85 		printf("Maybe you're not running as root?\n");
86 		return -1;
87 	}
88 
89 	for (i = 0; i < 5; i++) {
90 		printf("Using %i ppm adjustment\n", ppm[i]);
91 		ret = change_skew_test(ppm[i]);
92 		if (ret)
93 			break;
94 	}
95 
96 	/* Set things back */
97 	tx.modes = ADJ_FREQUENCY;
98 	tx.offset = 0;
99 	adjtimex(&tx);
100 
101 	if (ret) {
102 		printf("[FAIL]");
103 		return ksft_exit_fail();
104 	}
105 	printf("[OK]");
106 	return ksft_exit_pass();
107 }
108