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>

diff --git a/tools/testing/selftests/timers/leap-a-day.c b/tools/testing/selftests/timers/leap-a-day.c
index b8272e6..331c4f7 100644 (file)
--- a/tools/testing/selftests/timers/leap-a-day.c
+++ b/tools/testing/selftests/timers/leap-a-day.c
@@ -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;
        }