Hi,

I don't know if the following scenario should be handled by kernel but
here's the steps to reproduce the problem:

1. Make rtc-cmos module built-in, compile the kernel and install it onto
system,
2. Keep the rtc-cmos.ko which is ABI compatible with the current kernel
in /lib/modules/* so that it could be probed by udev,
3. Reboot the system. Kernel synchronizes the system clock from hardware
clock as it could access /dev/rtc0,
4. Udev (141) starts, the default rule for rtc* is processed which then
tries to modprobe rtc-cmos.ko which is still available in /lib/modules,
5. rtc-cmos.ko ooopses, the keyboard is dead, etc.

dmesg output is attached.

Thanks,
Ozan Caglayan