Re: kernel panic: uvm_fault

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

Thor Lancelot Simon wrote:
>On Mon, Jan 26, 2015 at 08:03:26PM +0100, Joerg Sonnenberger wrote:
>> On Mon, Jan 26, 2015 at 01:07:40PM -0500, Thor Lancelot Simon wrote:
>> > On Mon, Jan 26, 2015 at 04:28:22PM +0100, Thomas Klausner wrote:
>> > > On Mon, Jan 26, 2015 at 10:01:41AM -0500, Thor Lancelot Simon wrote:
>> > > > alloc_bouncebus?  On amd64?  I think you've got a trashed pointer
>> > > > somewhere.
>> > > 
>> > > I have
>> > > makeoptions   DEBUG="-g"      # compile full symbol table
>> > > 
>> > > # grep -r _bus_dma_alloc_bouncebuf /usr/src/sys/arch/amd64/
>> > > Binary file /usr/src/sys/arch/amd64/compile/obj/KERNELNAME/bus_dma.o matches
>> > 
>> > Yes, but why would you be trying to bounce PCI DMA on a 64-bit platform?
>> 
>> Because the device doesn't support 64bit DMA?
>
>That doesn't sound right for this device.

If there is an error in the normal route through bus_dmamap_load_mbuf
then it tries to use a bounce buffer. The code is shared with i386.

It looks to me as if it could be triggered by a mbuf with an invalid
size.