[PATCH 18/19] selftests/timers: Add set-2038 test from timetest suite

From: John Stultz
Date: Wed Mar 11 2015 - 20:40:45 EST


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@xxxxxxxxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
tools/testing/selftests/timers/Makefile | 3 +-
tools/testing/selftests/timers/set-2038.c | 144 ++++++++++++++++++++++++++++++
2 files changed, 146 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timers/set-2038.c

diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile
index 7e2fba7..9da3498 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 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}
diff --git a/tools/testing/selftests/timers/set-2038.c b/tools/testing/selftests/timers/set-2038.c
new file mode 100644
index 0000000..c8a7e14
--- /dev/null
+++ b/tools/testing/selftests/timers/set-2038.c
@@ -0,0 +1,144 @@
+/* Time bounds setting test
+ * by: john stultz (johnstul@xxxxxxxxxx)
+ * (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();
+}
--
1.9.1

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