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      1 /* ADJ_FREQ Skew change 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 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 argv, char **argc)
     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