Hello Alistair, On 07/02/2019 01:42, Alistair Francis wrote:> > Can you describe what this fixes? >
I encountered this problem when I tried to write 0xffffffffffffffff in timecmp. With the integer overflow in QEMU, writing this value means that the QEMU timer will be set in the past. > Won't an overflow be ok as we then just wrap around anyway? I guess > there is a problem if we want a value so large that we wrap around > past our current time though. > The overflow was in the computation of the value `next_ns`. It is used to set the QEMU timer: timer_mod(cpu->env.timer, next_ns); A negative `next_ns` -because of the overflow- means that the timer triggers immediately instead of far in the future. Regards,
