From owner-freebsd-current  Sat Jun 26 19:26:25 1999
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	Sun, 27 Jun 1999 12:26:11 +1000
Date: Sun, 27 Jun 1999 12:26:11 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199906270226.MAA10366@godzilla.zeta.org.au>
To: brdean@mindspring.com, freebsd-current@FreeBSD.ORG
Subject: Re: kernel panic w/regard to setting io permissions bitmap
Sender: owner-freebsd-current@FreeBSD.ORG
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>The panic occurs at 'swtch_com+0x6e: ltr %si'.  At the time, %si is
>0x20, which indexes to what appears to be a busy tss (type=01011b)
>with a limit of 0x67.  That instruction generates a general protection
>fault with an error code of 0.  The current process was Idle.
>...
>Perhaps someone could reproduce this and double check me?

Same here.  I think it is missing at least enlargement of the limit
of 0x67.

>Also ... I think I could analyze this better if I could break into the
>debugger and set a break point *before* the panic, and start tracing
>at the i386_set_ioperm() routine and follow what happens from there.
>Is there a function call that I can insert at the appropriate place to
>force dropping into the kernel debugger?

Just set a breakpoint:

    Ctrl-SysReq              enter ddb
    b i386_set_ioperm        set breakpoint
    c                        leave ddb

Bruce


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