mysterious "recoverable" page faults

[David Young <dyoung%pobox.com@localhost>]

I am tormented by mysterious page fault traps on a net4521.

The traps ordinarily occur at an instruction such as 'push %ebp'.
In ddb, 'show registers' displays sane-looking registers except for
ss:esp, which look like they have been scrambled.  If I type 'step' or
'continue', the page fault does not re-occur!  After 'step', eip has
increased by a predictable amount; ss:esp have taken a "normal" value,
and the other registers have not changed.

These traps often occur as the stack unwinds after transmitting an IP
packet.  It seems likely that NetBSD has serviced a network interrupt
while the stack unwound.

Does anyone have an idea of what could cause these "recoverable"
page faults?

Dave

-- 
David Young             OJC Technologies
dyoung%ojctech.com@localhost      Urbana, IL * (217) 278-3933 ext 24