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Date: Sun, 29 Sep 1996 18:20:41 -0700
From: Sean Eric Fagan <sef@Kithrup.COM>
Message-Id: <199609300120.SAA14731@kithrup.com>
To: hackers@freebsd.org
Subject: Help -- getting a panic in pmap_is_modified
Sender: owner-hackers@freebsd.org
X-Loop: FreeBSD.org
Precedence: bulk

I am getting a panic (in 2.1.5-RELEASE) in pmap_is_modified() during a
shutdown if I change struct trapframe.  (A page-not-present panic, in fact.)

In particular, I have added four words to the end of struct trapframe.  I've
compensated by also pushing four additional words in locore.s, just before
calling _main.

The annoying part is that it only happens when I shutdown; the code path is
calling through vfs_unmountroot().

I think it's safe to say that I've missed *somewhere* where the size of the
trapframe is important.  But I can't think of *where*.

I've asked both David and Bruce, and neither of them has any ideas.  Anyone
else?

Sean.