Re: diskless sparc locks up under memory pressure

[Valery Ushakov <uwe%stderr.spb.ru@localhost>]

On Sat, Nov 07, 2020 at 18:33:26 +0300, Valery Ushakov wrote:

> I've upgraded my Krups (64MB RAM, diskless) to 9.99.75 as of Nov 6 and
> the machine is locking up at boot time in rc.d/fccache.  If I disable
> fccache in rc.conf it boots but then eventually locks up when
> makemandb is run.  The machine doesn't respond to pings, etc, but can
> enter ddb.  In all cases the ddb stacktrace goes through:
> 
> ...
> uvm_fault_internal
> mem_access_fault4m
> memfault_sun4m
> copyout
> 
> with the top part of the stack trace varying.

This turned out to be unsafe inline asm in pmap code miscompiled by
the newer gcc.  Many thanks to chs@ for his help.

-uwe