On Mon, Dec 4, 2017 at 6:29 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Mon, Dec 4, 2017 at 1:55 AM, Deepa Dinamani <deepa.kernel@xxxxxxxxx> wrote: >> struct timeval is not y2038 safe. >> All usage of timeval in the kernel will be replaced by >> y2038 safe structures. >> The change is also necessary as glibc is introducing support >> for 32 bit applications to use 64 bit time_t. Without this >> change, many applications would incorrectly interpret values >> in the struct input_event. >> More details about glibc at >> https://sourceware.org/glibc/wiki/Y2038ProofnessDesign . >> >> struct input_event maintains time for each input event. >> Real time timestamps are not ideal for input as this >> time can go backwards as noted in the patch a80b83b7b8 >> by John Stultz. Hence, having the input_event.time fields >> only big enough for monotonic and boot times are >> sufficient. >> >> The change leaves the representation of struct input_event as is >> on 64 bit architectures. But uses 2 unsigned long values on 32 bit >> machines to support real timestamps until year 2106. >> This intentionally breaks the ABI on 32 bit architectures and >> compat handling on 64 bit architectures. >> This is as per maintainer's preference to introduce compile time errors >> rather than run into runtime incompatibilities. >> >> The change requires any 32 bit userspace utilities reading or writing >> from event nodes to update their reading format to match the new >> input_event. The changes to the popular libraries will be posted once >> we agree on the kernel change. >> >> Suggested-by: Arnd Bergmann <arnd@xxxxxxxx> >> Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx> > > Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx> > > This all looks good, I just have one small request: > >> - >> struct input_event { >> +#if __BITS_PER_LONG != 32 || !defined(__USE_TIME_BITS64) >> struct timeval time; >> +#define input_event_sec time.tv_sec >> +#define input_event_usec time.tv_usec >> +#else >> + __kernel_ulong_t __sec; >> + __kernel_ulong_t __usec; >> +#define input_event_sec __sec >> +#define input_event_usec __usec >> +#endif > > As we are getting closer to removing references to 'struct timeval' > from the kernel, could you rephrase that conditional to > > #if (__BITS_PER_LONG != 32 || !defined(__USE_TIME_BITS64)) && !defined(__KERNEL) Thanks. Will do. I just noticed that I left out the change to uinput for this patch. I will include that in the update as well. -Deepa -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
