Re: [Qemu-devel] Segfault using qemu-system-arm in smc91c111

[Richard Purdie <richard.purdie@linuxfoundation.org>]

On Fri, 2015-09-04 at 13:43 +0100, Richard Purdie wrote:
> On Fri, 2015-09-04 at 12:31 +0100, Peter Maydell wrote:
> > On 4 September 2015 at 12:24, Richard Purdie
> > <richard.purdie@linuxfoundation.org> wrote:
> > > So just based on that, yes, seems that the rx_fifo looks to be
> > > overrunning. I can add the asserts but I think it would just confirm
> > > this.
> > 
> > Yes, the point of adding assertions is to confirm a hypothesis.
> 
> I've now confirmed that it does indeed trigger the assert in
> smc91c111_receive().

I just tried an experiment where I put:

    if (s->rx_fifo_len >= NUM_PACKETS)
        return -1;

into smc91c111_receive() and my reproducer stops reproducing the
problem. I also noticed can_receive() could also have a check on buffer
availability. Would one of these changes be the correct fix here?

(Still working on a reproducer, ended up fixing the other test
continuation issues so the failure is more obvious).

Cheers,

Richard