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v5.4
  1/* Demo leapsecond deadlock
  2 *              by: John Stultz (john.stultz@linaro.org)
  3 *              (C) Copyright IBM 2012
  4 *              (C) Copyright 2013, 2015 Linaro Limited
  5 *              Licensed under the GPL
  6 *
  7 * This test demonstrates leapsecond deadlock that is possibe
  8 * on kernels from 2.6.26 to 3.3.
  9 *
 10 * WARNING: THIS WILL LIKELY HARDHANG SYSTEMS AND MAY LOSE DATA
 11 * RUN AT YOUR OWN RISK!
 12 *  To build:
 13 *	$ gcc leapcrash.c -o leapcrash -lrt
 14 */
 15
 16
 17
 18#include <stdio.h>
 19#include <stdlib.h>
 20#include <time.h>
 21#include <sys/time.h>
 22#include <sys/timex.h>
 23#include <string.h>
 24#include <signal.h>
 25#include "../kselftest.h"
 26
 27/* clear NTP time_status & time_state */
 28int clear_time_state(void)
 29{
 30	struct timex tx;
 31	int ret;
 32
 33	/*
 34	 * We have to call adjtime twice here, as kernels
 35	 * prior to 6b1859dba01c7 (included in 3.5 and
 36	 * -stable), had an issue with the state machine
 37	 * and wouldn't clear the STA_INS/DEL flag directly.
 38	 */
 39	tx.modes = ADJ_STATUS;
 40	tx.status = STA_PLL;
 41	ret = adjtimex(&tx);
 42
 43	tx.modes = ADJ_STATUS;
 44	tx.status = 0;
 45	ret = adjtimex(&tx);
 46
 47	return ret;
 48}
 49
 50/* Make sure we cleanup on ctrl-c */
 51void handler(int unused)
 52{
 53	clear_time_state();
 54	exit(0);
 55}
 56
 57
 58int main(void)
 59{
 60	struct timex tx;
 61	struct timespec ts;
 62	time_t next_leap;
 63	int count = 0;
 64
 65	setbuf(stdout, NULL);
 66
 67	signal(SIGINT, handler);
 68	signal(SIGKILL, handler);
 69	printf("This runs for a few minutes. Press ctrl-c to stop\n");
 70
 71	clear_time_state();
 72
 73
 74	/* Get the current time */
 75	clock_gettime(CLOCK_REALTIME, &ts);
 76
 77	/* Calculate the next possible leap second 23:59:60 GMT */
 78	next_leap = ts.tv_sec;
 79	next_leap += 86400 - (next_leap % 86400);
 80
 81	for (count = 0; count < 20; count++) {
 82		struct timeval tv;
 83
 84
 85		/* set the time to 2 seconds before the leap */
 86		tv.tv_sec = next_leap - 2;
 87		tv.tv_usec = 0;
 88		if (settimeofday(&tv, NULL)) {
 89			printf("Error: You're likely not running with proper (ie: root) permissions\n");
 90			return ksft_exit_fail();
 91		}
 92		tx.modes = 0;
 93		adjtimex(&tx);
 94
 95		/* hammer on adjtime w/ STA_INS */
 96		while (tx.time.tv_sec < next_leap + 1) {
 97			/* Set the leap second insert flag */
 98			tx.modes = ADJ_STATUS;
 99			tx.status = STA_INS;
100			adjtimex(&tx);
101		}
102		clear_time_state();
103		printf(".");
104		fflush(stdout);
105	}
106	printf("[OK]\n");
107	return ksft_exit_pass();
108}
v6.2
  1/* Demo leapsecond deadlock
  2 *              by: John Stultz (john.stultz@linaro.org)
  3 *              (C) Copyright IBM 2012
  4 *              (C) Copyright 2013, 2015 Linaro Limited
  5 *              Licensed under the GPL
  6 *
  7 * This test demonstrates leapsecond deadlock that is possible
  8 * on kernels from 2.6.26 to 3.3.
  9 *
 10 * WARNING: THIS WILL LIKELY HARD HANG SYSTEMS AND MAY LOSE DATA
 11 * RUN AT YOUR OWN RISK!
 12 *  To build:
 13 *	$ gcc leapcrash.c -o leapcrash -lrt
 14 */
 15
 16
 17
 18#include <stdio.h>
 19#include <stdlib.h>
 20#include <time.h>
 21#include <sys/time.h>
 22#include <sys/timex.h>
 23#include <string.h>
 24#include <signal.h>
 25#include "../kselftest.h"
 26
 27/* clear NTP time_status & time_state */
 28int clear_time_state(void)
 29{
 30	struct timex tx;
 31	int ret;
 32
 33	/*
 34	 * We have to call adjtime twice here, as kernels
 35	 * prior to 6b1859dba01c7 (included in 3.5 and
 36	 * -stable), had an issue with the state machine
 37	 * and wouldn't clear the STA_INS/DEL flag directly.
 38	 */
 39	tx.modes = ADJ_STATUS;
 40	tx.status = STA_PLL;
 41	ret = adjtimex(&tx);
 42
 43	tx.modes = ADJ_STATUS;
 44	tx.status = 0;
 45	ret = adjtimex(&tx);
 46
 47	return ret;
 48}
 49
 50/* Make sure we cleanup on ctrl-c */
 51void handler(int unused)
 52{
 53	clear_time_state();
 54	exit(0);
 55}
 56
 57
 58int main(void)
 59{
 60	struct timex tx;
 61	struct timespec ts;
 62	time_t next_leap;
 63	int count = 0;
 64
 65	setbuf(stdout, NULL);
 66
 67	signal(SIGINT, handler);
 68	signal(SIGKILL, handler);
 69	printf("This runs for a few minutes. Press ctrl-c to stop\n");
 70
 71	clear_time_state();
 72
 73
 74	/* Get the current time */
 75	clock_gettime(CLOCK_REALTIME, &ts);
 76
 77	/* Calculate the next possible leap second 23:59:60 GMT */
 78	next_leap = ts.tv_sec;
 79	next_leap += 86400 - (next_leap % 86400);
 80
 81	for (count = 0; count < 20; count++) {
 82		struct timeval tv;
 83
 84
 85		/* set the time to 2 seconds before the leap */
 86		tv.tv_sec = next_leap - 2;
 87		tv.tv_usec = 0;
 88		if (settimeofday(&tv, NULL)) {
 89			printf("Error: You're likely not running with proper (ie: root) permissions\n");
 90			return ksft_exit_fail();
 91		}
 92		tx.modes = 0;
 93		adjtimex(&tx);
 94
 95		/* hammer on adjtime w/ STA_INS */
 96		while (tx.time.tv_sec < next_leap + 1) {
 97			/* Set the leap second insert flag */
 98			tx.modes = ADJ_STATUS;
 99			tx.status = STA_INS;
100			adjtimex(&tx);
101		}
102		clear_time_state();
103		printf(".");
104		fflush(stdout);
105	}
106	printf("[OK]\n");
107	return ksft_exit_pass();
108}