Hi!
Some time ago I discovered strange output in boot messages, just as if the kernel trusts junk from hardware that is not present, like the RTC in a paravirtualized Xen guest (the guest has no /dev/rtc*). The message says:
<6>[ 0.123524] Time: 165:165:165 Date: 165/165/65
Obviously, if there were some validity check, this wouldn't pass, so I guess there is none!
In Xen's message buffer (hypervisor) I only see this error (that seems unrelated):
(XEN) mm.c:833:d6 Non-privileged (6) attempt to map I/O space 000000f0
According to my source code the print originates from read_magic_time() in /drivers/base/power/trace.c.
I'm running kernel 3.0.74-0.6.8-xen (SLES11 SP2) on x86_64.
Regards,
Ulrich