Re: LOR on head using virtualbox between intel kms and sound, with system lockup

On Sat, Dec 13, 2014 at 01:13:04AM +0100, Guido Falsi wrote:
> On 12/10/14 09:58, Guido Falsi wrote:
> > On 12/10/14 09:52, Konstantin Belousov wrote:
> >> On Tue, Dec 09, 2014 at 11:39:57PM +0100, Guido Falsi wrote:
> >>
> [...]
> >>> --- trap 0xc, tip = 0xffffffff8056834d, rsp = 0xfffffe022ed8f6b0, rbp =
> >>> 0xfffffe022ed8f6e0 ---
> >>> sbappendstream_locked() at sbappendstream_locked+0x2d/frame
> >>> 0xfffffe022ed8f6e0
> >>> sbappendstream() at sbappendstream+0x3c/frame 0xfffffe022ed8f710
> >>> tcp_usr_send() at tcp_usr_send+0x1ab/frame 0xfffffe022ed8f790
> >>> sosend_generic() at sosend_generic+0x40b/frame 0xfffffe022ed8f850
> >>> kern_sendit() at kern_sendit+0x19e/frame 0xfffffe022ed8f900
> >>> sendit() at sendit+0x129/frame 0xfffffe022ed8f950
> >>> sys_sendto() at sys_sendto+0x4d/frame 0xfffffe022ed8f9a0
> >>> amd64_syscall() at amd64_syscall+0x211/frame 0xfffffe022ed8fab0
> >>> Xfast_syscall() at Xfast_syscall+0xfb/frame 0xfffffe022ed8fab0
> >>> --- syscall (133, FreeBSD ELF64, sys_sendto), rip = 0x80126c5a, rsp =
> >>> 0x7fffdf1e9df8, rbp = 0x7fffdf1e9e40 ---
> 
> >> This is plain fault, in network stack, in the tcp send path. It has
> >> nothing to do with sound at all, and the LOR between DRM device lock and
> >> send buffer socket lock is a consequence of drm activated when panic
> >> occured in the locked region.
> >>
> >> That said, first thing to do when you experience panic with vbox or fuse
> >> modules loaded, is to remove the modules and see if it happens still.
> >> If it is persistent, contact net_at_.
> >>
> > 
> > I see. Problem with removing the virtualbox module is I have been able
> > to trigger the panic only by starting the VBox VM. I have no idea how to
> > trigger it some other way.
> > 
> > I'll try though.
> > 
> > Thanks for the insight!
> > 
> 
> Quick followup, for any interested party, I isolated the commit in
> r274712, reverting this one the problem disappears.
> 
> If anyone has some ideas about this please reply to me or followup in
> bug 195822 on bugzilla.
I suspect that the issue is vbox and not the revision itself.

Anyway, your best route is to ask Gleb.