Subject: Re: sh core dumps
To: None <port-sparc@netbsd.org>
From: Valeriy E. Ushakov <uwe@ptc.spbu.ru>
List: port-sparc
Date: 10/20/2005 17:14:59
On Wed, Oct 19, 2005 at 22:30:50 +0100, David Laight wrote:

> That value (in %g1) should (probably) never ever end up in a register
> in user-space.

Right.  And the address itself is weird.  It's an address of an
instruction in a delay slot in some unrelated inet6 function.  I don't
know how it can end up in a register even in the kernel.  The only
possibility that comes to mind is that a trap/interrupt happens while
that address is the npc (hardware will stuff it in %l2 before entering
trap handler) and then it ends up in the register through some
mischief.


> Those values for pc and npc are extremely unlikely to end up in the kernel.
> Two (obvious) possibilities:
> a) a hardware interrupt
> b) a fault on the previous instruction that happens after pc is incremented.

According to the trap information the fault is synchronous, so either
pc/npc are bogus, or there's a i-cache issue.


SY, Uwe
-- 
uwe@ptc.spbu.ru                         |       Zu Grunde kommen
http://www.ptc.spbu.ru/~uwe/            |       Ist zu Grunde gehen