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Date: Mon, 21 Apr 1997 18:52:09 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199704210852.SAA27852@godzilla.zeta.org.au>
To: freebsd-bugs@freebsd.org, Shimon@i-Connect.Net
Subject: Re: Mystery of the X11 Panic...
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[cc list trimmed to remove -hackers]

>Fatal trap 12 - Page fault while in kernel mode. in virtual address
>0xf71e0014.  Tracing back shows that bash (?!) was the culprit, causing it
>after calling _Xsyscall -> _syscall -> _vm_open -> _spec_open.
>
>Things go south at _spec_open + 0x6e, complaining about cmpl $0,0(%eax).

This means that cdevsw[maj]->d_open is bad (probably null) although
cdevsw[maj] != NULL.  This might be caused by a buggy or stale LKM.
Driver LKM's tend to cause this problem if they are unloaded.  Bash
may trigger the problem because it does an opendir() on device files
(but I thought I fixed this by not opening device files in opendir()).
I wouldn't use LKMs for anything important.

Bruce