/* Leap second stress test
* by: John Stultz (john.stultz@linaro.org)
* (C) Copyright IBM 2012
* (C) Copyright 2013, 2015 Linaro Limited
* Licensed under the GPLv2
*
* This test signals the kernel to insert a leap second
* every day at midnight GMT. This allows for stessing the
* kernel's leap-second behavior, as well as how well applications
* handle the leap-second discontinuity.
*
* Usage: leap-a-day [-s] [-i <num>]
*
* Options:
* -s: Each iteration, set the date to 10 seconds before midnight GMT.
* This speeds up the number of leapsecond transitions tested,
* but because it calls settimeofday frequently, advancing the
* time by 24 hours every ~16 seconds, it may cause application
* disruption.
*
* -i: Number of iterations to run (default: infinite)
*
* Other notes: Disabling NTP prior to running this is advised, as the two
* may conflict in their commands to the kernel.
*
* To build:
* $ gcc leap-a-day.c -o leap-a-day -lrt
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <sys/time.h>
#include <sys/timex.h>
#include <sys/errno.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include "../kselftest.h"
#define NSEC_PER_SEC 1000000000ULL
#define CLOCK_TAI 11
time_t next_leap;
int error_found;
/* returns 1 if a <= b, 0 otherwise */
static inline int in_order(struct timespec a, struct timespec b)
{
if (a.tv_sec < b.tv_sec)
return 1;
if (a.tv_sec > b.tv_sec)
return 0;
if (a.tv_nsec > b.tv_nsec)
return 0;
return 1;
}
struct timespec timespec_add(struct timespec ts, unsigned long long ns)
{
ts.tv_nsec += ns;
while (ts.tv_nsec >= NSEC_PER_SEC) {
ts.tv_nsec -= NSEC_PER_SEC;
ts.tv_sec++;
}
return ts;
}
char *time_state_str(int state)
{
switch (state) {
case TIME_OK: return "TIME_OK";
case TIME_INS: return "TIME_INS";
case TIME_DEL: return "TIME_DEL";
case TIME_OOP: return "TIME_OOP";
case TIME_WAIT: return "TIME_WAIT";
case TIME_BAD: return "TIME_BAD";
}
return "ERROR";
}
/* 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);
/* Clear maxerror, as it can cause UNSYNC to be set */
tx.modes = ADJ_MAXERROR;
tx.maxerror = 0;
ret = adjtimex(&tx);
/* Clear the status */
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);
}
void sigalarm(int signo)
{
struct timex tx;
int ret;
tx.modes = 0;
ret = adjtimex(&tx);
if (tx.time.tv_sec < next_leap) {
printf("Error: Early timer expiration! (Should be %ld)\n", next_leap);
error_found = 1;
printf("adjtimex: %10ld sec + %6ld us (%i)\t%s\n",
tx.time.tv_sec,
tx.time.tv_usec,
tx.tai,
time_state_str(ret));
}
if (ret != TIME_WAIT) {
printf("Error: Timer seeing incorrect NTP state? (Should be TIME_WAIT)\n");
error_found = 1;
printf("adjtimex: %10ld sec + %6ld us (%i)\t%s\n",
tx.time.tv_sec,
tx.time.tv_usec,
tx.tai,
time_state_str(ret));
}
}
/* Test for known hrtimer failure */
void test_hrtimer_failure(void)
{
struct timespec now, target;
clock_gettime(CLOCK_REALTIME, &now);
target = timespec_add(now, NSEC_PER_SEC/2);
clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &target, NULL);
clock_gettime(CLOCK_REALTIME, &now);
if (!in_order(target, now)) {
printf("ERROR: hrtimer early expiration failure observed.\n");
error_found = 1;
}
}
int main(int argc, char **argv)
{
timer_t tm1;
struct itimerspec its1;
struct sigevent se;
struct sigaction act;
int signum = SIGRTMAX;
int settime = 1;
int tai_time = 0;
int insert = 1;
int iterations = 10;
int opt;
/* Process arguments */
while ((opt = getopt(argc, argv, "sti:")) != -1) {
switch (opt) {
case 'w':
printf("Only setting leap-flag, not changing time. It could take up to a day for leap to trigger.\n");
settime = 0;
break;
case 'i':
iterations = atoi(optarg);
break;
case 't':
tai_time = 1;
break;
default:
printf("Usage: %s [-w] [-i <iterations>]\n", argv[0]);
printf(" -w: Set flag and wait for leap second each iteration");
printf(" (default sets time to right before leapsecond)\n");
printf(" -i: Number of iterations (-1 = infinite, default is 10)\n");
printf(" -t: Print TAI time\n");
exit(-1);
}
}
/* Make sure TAI support is present if -t was used */
if (tai_time) {
struct timespec ts;
if (clock_gettime(CLOCK_TAI, &ts)) {
printf("System doesn't support CLOCK_TAI\n");
ksft_exit_fail();
}
}
signal(SIGINT, handler);
signal(SIGKILL, handler);
/* Set up timer signal handler: */
sigfillset(&act.sa_mask);
act.sa_flags = 0;
act.sa_handler = sigalarm;
sigaction(signum, &act, NULL);
if (iterations < 0)
printf("This runs continuously. Press ctrl-c to stop\n");
else
printf("Running for %i iterations. Press ctrl-c to stop\n", iterations);
printf("\n");
while (1) {
int ret;
struct timespec ts;
struct timex tx;
time_t now;
/* 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);
if (settime) {
struct timeval tv;
tv.tv_sec = next_leap - 10;
tv.tv_usec = 0;
settimeofday(&tv, NULL);
printf("Setting time to %s", ctime(&tv.tv_sec));
}
/* Reset NTP time state */
clear_time_state();
/* Set the leap second insert flag */
tx.modes = ADJ_STATUS;
if (insert)
tx.status = STA_INS;
else
tx.status = STA_DEL;
ret = adjtimex(&tx);
if (ret < 0) {
printf("Error: Problem setting STA_INS/STA_DEL!: %s\n",
time_state_str(ret));
return ksft_exit_fail();
}
/* Validate STA_INS was set */
tx.modes = 0;
ret = adjtimex(&tx);
if (tx.status != STA_INS && tx.status != STA_DEL) {
printf("Error: STA_INS/STA_DEL not set!: %s\n",
time_state_str(ret));
return ksft_exit_fail();
}
if (tai_time) {
printf("Using TAI time,"
" no inconsistencies should be seen!\n");
}
printf("Scheduling leap second for %s", ctime(&next_leap));
/* Set up timer */
printf("Setting timer for %ld - %s", next_leap, ctime(&next_leap));
memset(&se, 0, sizeof(se));
se.sigev_notify = SIGEV_SIGNAL;
se.sigev_signo = signum;
se.sigev_value.sival_int = 0;
if (timer_create(CLOCK_REALTIME, &se, &tm1) == -1) {
printf("Error: timer_create failed\n");
return ksft_exit_fail();
}
its1.it_value.tv_sec = next_leap;
its1.it_value.tv_nsec = 0;
its1.it_interval.tv_sec = 0;
its1.it_interval.tv_nsec = 0;
timer_settime(tm1, TIMER_ABSTIME, &its1, NULL);
/* Wake up 3 seconds before leap */
ts.tv_sec = next_leap - 3;
ts.tv_nsec = 0;
while (clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &ts, NULL))
printf("Something woke us up, returning to sleep\n");
/* Validate STA_INS is still set */
tx.modes = 0;
ret = adjtimex(&tx);
if (tx.status != STA_INS && tx.status != STA_DEL) {
printf("Something cleared STA_INS/STA_DEL, setting it again.\n");
tx.modes = ADJ_STATUS;
if (insert)
tx.status = STA_INS;
else
tx.status = STA_DEL;
ret = adjtimex(&tx);
}
/* Check adjtimex output every half second */
now = tx.time.tv_sec;
while (now < next_leap + 2) {
char buf[26];
struct timespec tai;
int ret;
tx.modes = 0;
ret = adjtimex(&tx);
if (tai_time) {
clock_gettime(CLOCK_TAI, &tai);
printf("%ld sec, %9ld ns\t%s\n",
tai.tv_sec,
tai.tv_nsec,
time_state_str(ret));
} else {
ctime_r(&tx.time.tv_sec, buf);
buf[strlen(buf)-1] = 0; /*remove trailing\n */
printf("%s + %6ld us (%i)\t%s\n",
buf,
tx.time.tv_usec,
tx.tai,
time_state_str(ret));
}
now = tx.time.tv_sec;
/* Sleep for another half second */
ts.tv_sec = 0;
ts.tv_nsec = NSEC_PER_SEC / 2;
clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL);
}
/* Switch to using other mode */
insert = !insert;
/* Note if kernel has known hrtimer failure */
test_hrtimer_failure();
printf("Leap complete\n");
if (error_found) {
printf("Errors observed\n");
clear_time_state();
return ksft_exit_fail();
}
printf("\n");
if ((iterations != -1) && !(--iterations))
break;
}
clear_time_state();
return ksft_exit_pass();
}