Subject: Re: kernel: alignment fault trap on sparc
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Eduardo Horvath <eeh@NetBSD.org>
List: tech-kern
Date: 06/07/2004 18:26:38
On Mon, Jun 07, 2004 at 07:57:25PM +0200, Manuel Bouyer wrote:
> On Sat, Jun 05, 2004 at 07:16:25PM +0000, Eduardo Horvath wrote:
> > > No idea how this instruction could cause an alignment trap.
> >
> > sethi %hi(0xf02e3000), %l6 cannot generate an alignment fault. Only loads or
> > stores or possibly some sort of branches can generate alignment faults.
> >
> > You can try disassembling a few instructions surrounding the one that allegedly
> > caused the trap and see if one of them was the real culprit.
>
> How can I do that ??I didn't find anything in ddb to do disassembly, but I
> probably missed something.
x/i
(Or man ddb.)
> > Otherwise, it could be that the instruction in the instruction cache does not
> > match the contents in memory,
>
> Software bug ? we have had cache issues on sun4c in the past ...
Could be cache coherency issues.
> > or your CPU is getting old and flakey. I've seen
> > this happen a lot with old machines.
>
> I didn't have much problems with sparc yet. And this box started doing this
> right after the upgrade, it was solid under 1.6.2.
Could be a coincidence that the hardware broke at around the same time you
updated the software. I've seen that happen on occasion.
In any case, you need a proper crashdump analysis.
Eduardo