Re: crash by cdc_acm driver in kernels 4.8-rc1/5

[Alan Stern]

On Wed, 23 Nov 2016, [ISO-8859-1] Bjøork wrote:

> On November 23, 2016 1:54:57 AM CET, Wim Osterholt <wim@xxxxxxxxxxxxxx> wrote:
> >On Tue, Nov 22, 2016 at 07:08:30PM +0100, BjÃrn Mork wrote:
> >> > On kernel 4.8.8  this crashes hard and produces over a serial link:
> >> 
> >> Huh?  That device shouldn't ever enter that code path AFAICS.
> >> Unless.... you wouldn't happen to add a dynamic entry for this
> >device,
> >
> >No idea of what you mean here.
> >
> >> would you?  What's the output of
> >> 
> >>  cat /sys/bus/usb/drivers/cdc_acm/new_id
> >
> >Just empty.
> 
> Shit. Back to not understanding how you could possibly enter the debugging code at all.

You're in the lucky position of having an engaged and responsive bug
reporter who is willing to apply patches and run tests.  Just write a
simple diagnostic patch that will reveal exactly what pathway is being
followed.

Alan Stern