ntp: Fix integer overflow when setting time

'long secs' is passed as divisor to div_s64, which accepts a 32bit
divisor. On 64bit machines that value is trimmed back from 8 bytes
back to 4, causing a divide by zero when the number is bigger than
(1 << 32) - 1 and all 32 lower bits are 0.

Use div64_long() instead.

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Cc: johnstul@us.ibm.com
Link: http://lkml.kernel.org/r/1331829374-31543-2-git-send-email-levinsasha928@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Sasha Levin 2012-03-15 12:36:14 -04:00 коммит произвёл Thomas Gleixner
Родитель f910381a55
Коммит a078c6d0e6
1 изменённых файлов: 1 добавлений и 1 удалений

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@ -289,7 +289,7 @@ static inline s64 ntp_update_offset_fll(s64 offset64, long secs)
time_status |= STA_MODE;
return div_s64(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
return div64_long(offset64 << (NTP_SCALE_SHIFT - SHIFT_FLL), secs);
}
static void ntp_update_offset(long offset)