kern/42550: possible year2038 problem in MI todr(9)

[tsutsui%ceres.dti.ne.jp@localhost]

>Number:         42550
>Category:       kern
>Synopsis:       possible year2038 problem in MI todr(9)
>Confidential:   no
>Severity:       critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Thu Dec 31 07:05:00 +0000 2009
>Originator:     Izumi Tsutsui
>Release:        NetBSD 5.99.22
>Organization:
>Environment:
System: NetBSD 5.99.22 updated around 20091223
Architecture: sparc
Machine: sparc
With:
mainbus0 (root): SUNW,SPARCstation-20
clock0 at obio0 slot 0 offset 0x200000: mk48t08

>Description:
MI todr(9) routines seem to have some problem at least
on SPARCstation 20 with mk48txx(4) todr clock device.

The kernel hangs if TODR date is >2038 right after mountroot
and even after date is set >2038.

>How-To-Repeat:
# date
Thu Dec 31 06:52:04 UTC 2009
# date 200912310000.00
Thu Dec 31 00:00:00 UTC 2009
# date 203812310000.00
#   [... kernel hangs here]

Reboot machine at this point, then it hangs after mountroot.

Booting netbsd-5 kernel will reset the TODR clock
using file system time, and then it fixes the hangup.

I saw similar hang on mac68k with dead battery
and the problem was resolved after TOD value was corrected.

>Fix:
Unknown. Check all possible 32bit overflow?