Andreas Schwab noted that the 1 << tk->shift could overflow
if the shift value was greater then 30, since 1 would be
a 32bit long on 32bit architectures.
This patch uses 1ULL instead to ensure we don't overflow on
the shift.
This issue was introduced by 1e75fa8be9fb61e1af46b5b3b176347a4c958ca1
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Prarit Bhargava <pra...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Andreas Schwab <sch...@linux-m68k.org>
Reported-by: Andreas Schwab <sch...@linux-m68k.org>
Signed-off-by: John Stultz <john.stu...@linaro.org>
---
kernel/time/timekeeping.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 1dbf80e..a5a9389 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1184,9 +1184,9 @@ static void update_wall_time(void)
* the vsyscall implementations are converted to use xtime_nsec
* (shifted nanoseconds), this can be killed.
*/
- remainder = tk->xtime_nsec & ((1 << tk->shift) - 1);
+ remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
tk->xtime_nsec -= remainder;
- tk->xtime_nsec += 1 << tk->shift;
+ tk->xtime_nsec += 1ULL << tk->shift;
tk->ntp_error += remainder << tk->ntp_error_shift;
/*
--
1.7.9.5
--
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