qemu/0308-rtc-fix-overflow-in-mktimegm.patch

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From 6dfc8874df8648e37f19f099cb8c2efee19bcee3 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Mon, 1 Oct 2012 14:22:06 +0200
Subject: [PATCH] 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>
(cherry picked from commit b6db4aca20e9af4f62c9c9e08b9b9672a6ed3390)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
cutils.c | 2 +-
tests/rtc-test.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 46 insertions(+), 1 deletion(-)
diff --git a/cutils.c b/cutils.c
index 8ef648f..8edd8fa 100644
--- a/cutils.c
+++ b/cutils.c
@@ -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 f23ac3a..2b9aa63 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();