diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2012-10-01 14:22:06 +0200 |
|---|---|---|
| committer | Anthony Liguori <aliguori@us.ibm.com> | 2012-10-05 08:02:30 -0500 |
| commit | b6db4aca20e9af4f62c9c9e08b9b9672a6ed3390 (patch) | |
| tree | c720251bf1c6e4aa90b391fe80f8a7fb8b280792 | |
| parent | e0fea6b1e4df2067a51e08e67a17cb98a547287c (diff) | |
rtc: fix overflow in mktimegm
When setting a date in 1980, Linux is actually disregarding the century
byte and setting the year to 2080. This causes a year-2038 overflow
in mktimegm. Fix this by doing the days-to-seconds computation in
64-bit math.
Reported-by: Lucas Meneghel Rodrigues <lookkas@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
| -rw-r--r-- | cutils.c | 2 | ||||
| -rw-r--r-- | tests/rtc-test.c | 45 |
2 files changed, 46 insertions, 1 deletions
@@ -115,7 +115,7 @@ time_t mktimegm(struct tm *tm) m += 12; y--; } - t = 86400 * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + + t = 86400ULL * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + y / 400 - 719469); t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec; return t; diff --git a/tests/rtc-test.c b/tests/rtc-test.c index f23ac3a6cf..2b9aa63c1f 100644 --- a/tests/rtc-test.c +++ b/tests/rtc-test.c @@ -179,6 +179,50 @@ static void check_time(int wiggle) static int wiggle = 2; +static void set_year(void) +{ + /* Set BCD mode */ + cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) & ~REG_B_DM); + cmos_write(RTC_REG_A, 0x76); + cmos_write(RTC_YEAR, 0x11); + cmos_write(RTC_MONTH, 0x02); + cmos_write(RTC_DAY_OF_MONTH, 0x02); + cmos_write(RTC_HOURS, 0x02); + cmos_write(RTC_MINUTES, 0x04); + cmos_write(RTC_SECONDS, 0x58); + cmos_write(RTC_REG_A, 0x26); + + g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04); + g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58); + g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x11); + + /* Set a date in 2080 to ensure there is no year-2038 overflow. */ + cmos_write(RTC_REG_A, 0x76); + cmos_write(RTC_YEAR, 0x80); + cmos_write(RTC_REG_A, 0x26); + + g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04); + g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58); + g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x80); + + cmos_write(RTC_REG_A, 0x76); + cmos_write(RTC_YEAR, 0x11); + cmos_write(RTC_REG_A, 0x26); + + g_assert_cmpint(cmos_read(RTC_HOURS), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MINUTES), ==, 0x04); + g_assert_cmpint(cmos_read(RTC_SECONDS), >=, 0x58); + g_assert_cmpint(cmos_read(RTC_DAY_OF_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_MONTH), ==, 0x02); + g_assert_cmpint(cmos_read(RTC_YEAR), ==, 0x11); +} + static void bcd_check_time(void) { /* Set BCD mode */ @@ -269,6 +313,7 @@ int main(int argc, char **argv) qtest_add_func("/rtc/bcd/check-time", bcd_check_time); qtest_add_func("/rtc/dec/check-time", dec_check_time); qtest_add_func("/rtc/alarm-time", alarm_time); + qtest_add_func("/rtc/set-year", set_year); qtest_add_func("/rtc/fuzz-registers", fuzz_registers); ret = g_test_run(); |