Page map BUG on program exit

[Jonathan Haws]

All,

I am using a 405EX CPU on a custom board.  The layout and hardware is very similar to the AMCC Kilauea board.  Here is the output of uname -a:

Linux (none) 2.6.30.3-wolverine-dirty #3 PREEMPT Thu Sep 10 11:41:37 MDT 2009 ppc unknown

I am getting the following BUG output when my program exits:

BUG: Bad page map in process main  pte:980005d7 pmd:0d840400
addr:48000000 vm_flags:400844fb anon_vma:(null) mapping:cd8454f8 index:98000
vma->vm_file->f_op->mmap: fpga_mmap+0x0/0x178 [fpgaDriver]
Call Trace:
[cd84dc40] [c0006f0c] show_stack+0x44/0x16c (unreliable)
[cd84dc80] [c00ba314] print_bad_pte+0x140/0x1d0
[cd84dcb0] [c00ba3ec] vm_normal_page+0x48/0x50
[cd84dcc0] [c00bb2ec] unmap_vmas+0x214/0x614
[cd84dd40] [c00bffe0] exit_mmap+0xd0/0x1b4
[cd84dd70] [c0031e40] mmput+0x50/0x134
[cd84dd80] [c0036470] exit_mm+0x114/0x13c
[cd84ddb0] [c0037d80] do_exit+0xc0/0x68c
[cd84de00] [c0038390] do_group_exit+0x44/0xd8
[cd84de10] [c0044468] get_signal_to_deliver+0x1f8/0x430
[cd84de70] [c0008224] do_signal+0x54/0x29c
[cd84df40] [c0010d5c] do_user_signal+0x74/0xc4

I have an FPGA on the PCIe bus that I am mapping BAR0 to user space with a call to mmap().  The mapping works just fine and I can access all the registers in the BAR without a problem.  However, on exit this comes up.

A Google search showed tons of people with similar problems in standard distributions (Ubuntu primarily), but no resolutions.

Has anyone seen this crop up before and know what the issue is?  I include any source code, if that is required.

Thanks!

Jonathan