120 lines
2.3 KiB
C
120 lines
2.3 KiB
C
/* Demo leapsecond deadlock
|
|
* by: John Stultz (john.stultz@linaro.org)
|
|
* (C) Copyright IBM 2012
|
|
* (C) Copyright 2013, 2015 Linaro Limited
|
|
* Licensed under the GPL
|
|
*
|
|
* This test demonstrates leapsecond deadlock that is possibe
|
|
* on kernels from 2.6.26 to 3.3.
|
|
*
|
|
* WARNING: THIS WILL LIKELY HARDHANG SYSTEMS AND MAY LOSE DATA
|
|
* RUN AT YOUR OWN RISK!
|
|
* To build:
|
|
* $ gcc leapcrash.c -o leapcrash -lrt
|
|
*/
|
|
|
|
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <time.h>
|
|
#include <sys/time.h>
|
|
#include <sys/timex.h>
|
|
#include <string.h>
|
|
#include <signal.h>
|
|
#ifdef KTEST
|
|
#include "../kselftest.h"
|
|
#else
|
|
static inline int ksft_exit_pass(void)
|
|
{
|
|
exit(0);
|
|
}
|
|
static inline int ksft_exit_fail(void)
|
|
{
|
|
exit(1);
|
|
}
|
|
#endif
|
|
|
|
|
|
|
|
/* clear NTP time_status & time_state */
|
|
int clear_time_state(void)
|
|
{
|
|
struct timex tx;
|
|
int ret;
|
|
|
|
/*
|
|
* We have to call adjtime twice here, as kernels
|
|
* prior to 6b1859dba01c7 (included in 3.5 and
|
|
* -stable), had an issue with the state machine
|
|
* and wouldn't clear the STA_INS/DEL flag directly.
|
|
*/
|
|
tx.modes = ADJ_STATUS;
|
|
tx.status = STA_PLL;
|
|
ret = adjtimex(&tx);
|
|
|
|
tx.modes = ADJ_STATUS;
|
|
tx.status = 0;
|
|
ret = adjtimex(&tx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Make sure we cleanup on ctrl-c */
|
|
void handler(int unused)
|
|
{
|
|
clear_time_state();
|
|
exit(0);
|
|
}
|
|
|
|
|
|
int main(void)
|
|
{
|
|
struct timex tx;
|
|
struct timespec ts;
|
|
time_t next_leap;
|
|
int count = 0;
|
|
|
|
setbuf(stdout, NULL);
|
|
|
|
signal(SIGINT, handler);
|
|
signal(SIGKILL, handler);
|
|
printf("This runs for a few minutes. Press ctrl-c to stop\n");
|
|
|
|
clear_time_state();
|
|
|
|
|
|
/* Get the current time */
|
|
clock_gettime(CLOCK_REALTIME, &ts);
|
|
|
|
/* Calculate the next possible leap second 23:59:60 GMT */
|
|
next_leap = ts.tv_sec;
|
|
next_leap += 86400 - (next_leap % 86400);
|
|
|
|
for (count = 0; count < 20; count++) {
|
|
struct timeval tv;
|
|
|
|
|
|
/* set the time to 2 seconds before the leap */
|
|
tv.tv_sec = next_leap - 2;
|
|
tv.tv_usec = 0;
|
|
if (settimeofday(&tv, NULL)) {
|
|
printf("Error: You're likely not running with proper (ie: root) permissions\n");
|
|
return ksft_exit_fail();
|
|
}
|
|
tx.modes = 0;
|
|
adjtimex(&tx);
|
|
|
|
/* hammer on adjtime w/ STA_INS */
|
|
while (tx.time.tv_sec < next_leap + 1) {
|
|
/* Set the leap second insert flag */
|
|
tx.modes = ADJ_STATUS;
|
|
tx.status = STA_INS;
|
|
adjtimex(&tx);
|
|
}
|
|
clear_time_state();
|
|
printf(".");
|
|
}
|
|
printf("[OK]\n");
|
|
return ksft_exit_pass();
|
|
}
|