Messages in this thread Patch in this message | | | From | Andreas Schwab <> | Subject | [PATCH] time: Fix casting issue in timekeeping_forward_now | Date | Sun, 19 Aug 2012 22:09:01 +0200 |
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arch_gettimeoffset returns a u32 value which when shifted by tk->shift can overflow. Cast it to u64 first.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org> --- Found this by inspection, I don't know if any existing users of ARCH_USES_GETTIMEOFFSET are affected. In other words, this is untested, but looks pretty obvious.
Can tk->shift be bigger than 30? If so then the shifts in update_wall_time need to be adjusted as well.
Andreas.
--- kernel/time/timekeeping.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index e16af19..8776d66 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -276,7 +276,7 @@ static void timekeeping_forward_now(struct timekeeper *tk) tk->xtime_nsec += cycle_delta * tk->mult; /* If arch requires, add in gettimeoffset() */ - tk->xtime_nsec += arch_gettimeoffset() << tk->shift; + tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift; tk_normalize_xtime(tk); -- 1.7.11.5 -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."
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