Subject: Re: Another crash, current-940425
To: None <>
From: Michael L. VanLoon -- Iowa State University <>
List: current-users
Date: 04/26/1994 22:44:27
Mark Weaver writes:
>This happened while asking emacs-19.22 to create a new screen on an X
>terminal over a SLIP connection.
>panic: free: multiple frees
>Stopped at      _Debugger+0x4:  leave

You actually got it to run at all?  Every kernel I've built since the
weekend drops into the kernel debugger seconds after starting the
first fsck.  I'm still running Sunday's kernel.

Monday and today's kernel do this to me right after autoconfig, right
as it's beginning to fsck:

	vm_fault(f83d2a00, 0, 1, 0) -> 1
	kernel: page fault trap, code=0
	Stopped at    _uiomove+0x13:  cmpl $0x1,0x18(%edi)

	in syscall 5

The edi register contains 0 (is NULL).  It appears edi is the uio
pointer, so it's resolving a NULL reference:

        if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
                panic("uiomove: mode");

I suppose if I removed DIAGNOSTIC from my kernel config it might run,
but I'd rather know when things aren't working right inside.


 Michael L. VanLoon                 Iowa State University Computation Center                    Project Vincent Systems Staff
  Free your mind and your machine -- NetBSD free Un*x for PC/Mac/Amiga/etc.