On Fri, Nov 08, 2019 at 09:34:28PM +0100, Arnd Bergmann wrote: > The current xt_time driver suffers from the y2038 overflow on 32-bit > architectures, when the time of day calculations break. > > Also, on both 32-bit and 64-bit architectures, there is a problem with > info->date_start/stop, which is part of the user ABI and overflows in > in 2106. > > Fix the first issue by using time64_t and explicit calls to div_u64() > and div_u64_rem(), and document the seconds issue. > > The explicit 64-bit division is unfortunately slower on 32-bit > architectures, but doing it as unsigned lets us use the optimized > division-through-multiplication path in most configurations. This should > be fine, as the code already does not allow any negative time of day > values. > > Using u32 seconds values consistently would probably also work and > be a little more efficient, but that doesn't feel right as it would > propagate the y2106 overflow to more place rather than fewer. Applied, thanks.
