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Date: Mon, 22 Sep 1997 00:20:37 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199709211420.AAA01820@godzilla.zeta.org.au>
To: cgull+usenet-876050826@smoke.marlboro.vt.us, current@FreeBSD.ORG,
        jkh@FreeBSD.ORG
Subject: Re: 970919 snapshot install panic
Sender: owner-freebsd-current@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

>current process = 43 (sh)
>interrupt mask =			(yup, that's blank)

I don't know about the other problems, but a blank mask means that something
other than net, tty or bio is masked, probably just ASTs.  This is normal
for panics in kernel mode (except while processing interrupts of course).
It is normal for panics in user mode too, since the current mask is printed,
and SWI_AST_MASK is always set for trap handling.  The "none" case in
trap_fatal() is unreachable.

Fixes: get the previous mask from the trap frame, and maybe print
more masks.  Some of the masks depend on the others (e.g., softclock
interrupts are masked if any other interrupt is masked), but this is
already a problem (e.g., "net" is usually equivalent to "tty", but
printing of one does not prevent printing of the other).

Bruce