hangs and segfaults

Hello,

I'm running a recent version of 6.1_STABLE on sparc64, Sun Ultra10. This
is GENERIC.UP kernel. I've been having issues with processes hanging or
segfaulting. This tends to happen to gcc process while building from
pkgsrc.

I suspect this could be a hardware problem, however I ran memtester over
several days and it didn't find any issues.

This is what I'm currently observing, gcc process stuck on CPU in an
infinite loop

  PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU
COMMAND 10946 root       9   20    25M   17M RUN      692:51 99.02%
99.02% cc1

Everything else runs normally and the system functions without any
issues.

I've also noticed the following logged, when I had a segfault
previously:

Mar  5 00:07:51 ultra10 /netbsd: text_access_error: memory error...
Mar  5 00:07:51 ultra10 /netbsd: text memory error type 10 sfsr=0
sfva=414c7c afsr=17ff7b6fbf8 afva=100400002 tf=0x3153fed0


Could this be a kernel bug somewhere, or is it more likely to be a
hardware issue?

Thanks.