selftests: timers: Add leap-second timer edge testing to leap-a-day.c

Prarit reported an issue w/ timers around the leapsecond, where a
timer set for Midnight UTC (00:00:00) might fire a second early right
before the leapsecond (23:59:60 - though it appears as a repeated
23:59:59) is applied.

So I've updated the leap-a-day.c test to integrate a similar test,
where we set a timer and check if it triggers at the right time, and
if the ntp state transition is managed properly.

Reported-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Bohac <jbohac@suse.cz>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/1434063297-28657-6-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
John Stultz 2015-06-11 15:54:57 -07:00 committed by Thomas Gleixner
parent 96efdcf2d0
commit 0c4a5fc95b

View file

@ -44,6 +44,7 @@
#include <time.h>
#include <sys/time.h>
#include <sys/timex.h>
#include <sys/errno.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
@ -63,6 +64,9 @@ static inline int ksft_exit_fail(void)
#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)
{
@ -134,6 +138,34 @@ void handler(int unused)
exit(0);
}
void sigalarm(int signo)
{
struct timex tx;
char buf[26];
int ret;
tx.modes = 0;
ret = adjtimex(&tx);
ctime_r(&tx.time.tv_sec, buf);
buf[strlen(buf)-1] = 0; /*remove trailing\n */
printf("%s + %6ld us (%i)\t%s - TIMER FIRED\n",
buf,
tx.time.tv_usec,
tx.tai,
time_state_str(ret));
if (tx.time.tv_sec < next_leap) {
printf("Error: Early timer expiration!\n");
error_found = 1;
}
if (ret != TIME_WAIT) {
printf("Error: Incorrect NTP state?\n");
error_found = 1;
}
}
/* Test for known hrtimer failure */
void test_hrtimer_failure(void)
{
@ -144,12 +176,19 @@ void test_hrtimer_failure(void)
clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &target, NULL);
clock_gettime(CLOCK_REALTIME, &now);
if (!in_order(target, 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 = 0;
int tai_time = 0;
int insert = 1;
@ -191,6 +230,12 @@ int main(int argc, char **argv)
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
@ -201,7 +246,7 @@ int main(int argc, char **argv)
int ret;
struct timespec ts;
struct timex tx;
time_t now, next_leap;
time_t now;
/* Get the current time */
clock_gettime(CLOCK_REALTIME, &ts);
@ -251,10 +296,27 @@ int main(int argc, char **argv)
printf("Scheduling leap second for %s", ctime(&next_leap));
/* Set up timer */
printf("Setting timer for %s", 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");
@ -276,6 +338,7 @@ int main(int argc, char **argv)
while (now < next_leap + 2) {
char buf[26];
struct timespec tai;
int ret;
tx.modes = 0;
ret = adjtimex(&tx);
@ -308,8 +371,13 @@ int main(int argc, char **argv)
/* Note if kernel has known hrtimer failure */
test_hrtimer_failure();
printf("Leap complete\n\n");
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;
}