selftests/timers: Add leapcrash test from the timetest suite

This change adds the leapcrash test which tests to see if a
leapsecond deadlock which was observed from 2.6.26 to 3.3
is present on this system.

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

2 files changed, 122 insertions, 1 deletions

diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index da35dddaa985..d73332495c2e 100644
--- a/tools/testing/selftests/timers/Makefile
+++ b/tools/testing/selftests/timers/Makefile
@@ -5,7 +5,7 @@ LDFLAGS += -lrt -lpthread
 bins = posix_timers nanosleep inconsistency-check nsleep-lat raw_skew \
         set-timer-lat threadtest mqueue-lat valid-adjtimex \
         alarmtimer-suspend change_skew skew_consistency clocksource-switch \
-        leap-a-day
+        leap-a-day leapcrash
 
 all: ${bins}
 
@@ -31,6 +31,7 @@ run_destructive_tests: run_tests
         ./skew_consistency
         ./clocksource-switch
         ./leap-a-day -s -i 10
+        ./leapcrash
 
 clean:
         rm -f ${bins}
diff --git a/tools/testing/selftests/timers/leapcrash.c b/tools/testing/selftests/timers/leapcrash.c
new file mode 100644
index 000000000000..a1071bdbdeb7
--- /dev/null
+++ b/tools/testing/selftests/timers/leapcrash.c
@@ -0,0 +1,120 @@
+/* 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();
+}