kern/41342: BSDi binaries cause panic

[marcotte%panix.com@localhost]

>Number:         41342
>Category:       kern
>Synopsis:       BSDi binaries cause panic
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun May 03 07:15:00 +0000 2009
>Originator:     Brian Marcotte
>Release:        NetBSD 5.0
>Organization:
Panix
>Environment:
NetBSD www.panix.com 5.0 NetBSD 5.0 (PANIX-XEN3U-WEB) #0: Tue Apr 28 20:29:19 
EDT 2009  
root%juggler.panix.com@localhost:/misc3/obj/misc2/devel/netbsd/5.0/src/sys/arch/i386/compile/PANIX-XEN3U-WEB
 i386
>Description:
BSDi binaries segfault or even panic the system on NetBSD 5.0.

Under Xen, the kernel will panic:
    fatal protection fault in supervisor mode
    trap type 4 code 0 eip c01001f0 cs 9 eflags 10286 cr2 7514 ilevel 0
    panic: trap
    Begin traceback...
    End traceback...

When I told it to drop to DDB so I could try to get a trace, I got this:
  Xosyscall(17,12af,bf7ff9f0,1f,0,0,0,0,d104ad90,d104a4f4) at netbsd:Xosyscall
  ?(1,bf7ffa80,bf7ffa88,bf7ffff0,0,0,1,bf7ffb00,0,bf7ffb0a) at 0x18e5
  
?(bf7ffb00,0,bf7ffb0a,bf7ffb2c,bf7ffb44,bf7ffc1c,bf7ffc5c,bf7ffc7e,bf7ffcb5,bf7ffcd2)
 at 0x1097

I've tracked this down to the commit described in this message:

    http://mail-index.netbsd.org/source-changes/2009/04/04/msg219192.html

which was done to fix PR 40143 (Viewing an mpeg transport stream with mplayer 
causes crash).

>How-To-Repeat:
Grab a sample binary from http://www.panix.com/~marcotte/bsdi/architextIndex.

When NetBSD 5.0 is running on hardware, the binary will segfault. When
the system is a Xen domU, the kernel will panic. Under previous versions
of NetBSD, it works fine and will print "Must specify root index
filename".

>Fix: