selftests/timers: Add set-2038 test from timetest suite

Adds the set-2038 test which sets the time to near-edge cases
like the start and end of the 32 bit epoch and checks that
time behaves properly. There is also a dangerous mode, which
lets the clock roll over past 2038 on 32bit systems, which
on some older kernels will cause system hangs.

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>

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 leapcrash set-tai
+	leap-a-day leapcrash set-tai set-2038
 
 all: ${bins}
 
@@ -33,6 +33,7 @@ run_destructive_tests: run_tests
 	./leap-a-day -s -i 10
 	./leapcrash
 	./set-tai
+	./set-2038
 
 clean:
 	rm -f ${bins}

tools/testing/selftests/timers/set-2038.c

@@ -0,0 +1,144 @@
+/* Time bounds setting test
+ *		by: john stultz (johnstul@us.ibm.com)
+ *		(C) Copyright IBM 2012
+ *		Licensed under the GPLv2
+ *
+ *  NOTE: This is a meta-test which sets the time to edge cases then
+ *  uses other tests to detect problems. Thus this test requires that
+ *  the inconsistency-check and nanosleep tests be present in the same
+ *  directory it is run from.
+ *
+ *  To build:
+ *	$ gcc set-2038.c -o set-2038 -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 <unistd.h>
+#include <time.h>
+#include <sys/time.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
+
+#define NSEC_PER_SEC 1000000000LL
+
+#define KTIME_MAX	((long long)~((unsigned long long)1 << 63))
+#define KTIME_SEC_MAX	(KTIME_MAX / NSEC_PER_SEC)
+
+#define YEAR_1901 (-0x7fffffffL)
+#define YEAR_1970 1
+#define YEAR_2038 0x7fffffffL			/*overflows 32bit time_t */
+#define YEAR_2262 KTIME_SEC_MAX			/*overflows 64bit ktime_t */
+#define YEAR_MAX  ((long long)((1ULL<<63)-1))	/*overflows 64bit time_t */
+
+int is32bits(void)
+{
+	return (sizeof(long) == 4);
+}
+
+int settime(long long time)
+{
+	struct timeval now;
+	int ret;
+
+	now.tv_sec = (time_t)time;
+	now.tv_usec  = 0;
+
+	ret = settimeofday(&now, NULL);
+
+	printf("Setting time to 0x%lx: %d\n", (long)time, ret);
+	return ret;
+}
+
+int do_tests(void)
+{
+	int ret;
+
+	ret = system("date");
+	ret = system("./inconsistency-check -c 0 -t 20");
+	ret |= system("./nanosleep");
+	ret |= system("./nsleep-lat");
+	return ret;
+
+}
+
+int main(int argc, char *argv[])
+{
+	int ret = 0;
+	int opt, dangerous = 0;
+	time_t start;
+
+	/* Process arguments */
+	while ((opt = getopt(argc, argv, "d")) != -1) {
+		switch (opt) {
+		case 'd':
+			dangerous = 1;
+		}
+	}
+
+	start = time(0);
+
+	/* First test that crazy values don't work */
+	if (!settime(YEAR_1901)) {
+		ret = -1;
+		goto out;
+	}
+	if (!settime(YEAR_MAX)) {
+		ret = -1;
+		goto out;
+	}
+	if (!is32bits() && !settime(YEAR_2262)) {
+		ret = -1;
+		goto out;
+	}
+
+	/* Now test behavior near edges */
+	settime(YEAR_1970);
+	ret = do_tests();
+	if (ret)
+		goto out;
+
+	settime(YEAR_2038 - 600);
+	ret = do_tests();
+	if (ret)
+		goto out;
+
+	/* The rest of the tests can blowup on 32bit systems */
+	if (is32bits() && !dangerous)
+		goto out;
+	/* Test rollover behavior 32bit edge */
+	settime(YEAR_2038 - 10);
+	ret = do_tests();
+	if (ret)
+		goto out;
+
+	settime(YEAR_2262 - 600);
+	ret = do_tests();
+
+out:
+	/* restore clock */
+	settime(start);
+	if (ret)
+		return ksft_exit_fail();
+	return ksft_exit_pass();
+}