Re: arm: pmap uvm_fault findings

2016-07-30 Thread Artturi Alm
On Sat, Jul 30, 2016 at 03:10:45PM +0200, Mark Kettenis wrote: > > From: Philip Guenther > > Date: Fri, 29 Jul 2016 15:41:48 -0700 > > > > On Fri, Jul 29, 2016 at 3:31 PM, Mark Kettenis > > wrote: > > >> Date: Thu, 28 Jul 2016 09:47:42 +0200 > > >>

Re: arm: pmap uvm_fault findings

2016-07-30 Thread Mark Kettenis
> From: Philip Guenther > Date: Fri, 29 Jul 2016 15:41:48 -0700 > > On Fri, Jul 29, 2016 at 3:31 PM, Mark Kettenis > wrote: > >> Date: Thu, 28 Jul 2016 09:47:42 +0200 > >> From: Patrick Wildt > >> > >> There is something I missed

Re: arm: pmap uvm_fault findings

2016-07-29 Thread Philip Guenther
On Fri, Jul 29, 2016 at 3:31 PM, Mark Kettenis wrote: >> Date: Thu, 28 Jul 2016 09:47:42 +0200 >> From: Patrick Wildt >> >> There is something I missed in the previous diff. When the PTE is not >> valid, the mapping behind the virtual address of

Re: arm: pmap uvm_fault findings

2016-07-29 Thread Mark Kettenis
> Date: Thu, 28 Jul 2016 09:47:42 +0200 > From: Patrick Wildt > > There is something I missed in the previous diff. When the PTE is not > valid, the mapping behind the virtual address of course isn't valid. > A flush to an unmapped page will give us a translation fault. So

Re: arm: pmap uvm_fault findings

2016-07-28 Thread Patrick Wildt
On Wed, Jul 27, 2016 at 08:06:57PM +0200, Patrick Wildt wrote: > On Tue, Jul 26, 2016 at 06:43:18PM +0200, Patrick Wildt wrote: > > Hi, > > > > I've been trying to debug a pmap issue on ARM. I have no solution, but > > I would like to share my findings so far. > > > > First of all, the

Re: arm: pmap uvm_fault findings

2016-07-27 Thread Daniel Bolgheroni
On Wed, Jul 27, 2016 at 08:06:57PM +0200, Patrick Wildt wrote: > > There are more places in that pmap where we explicitly check for zero > and not for being valid. Unfortunately this place was missed. Wandboard with your patch, recompiling a kernel, and no problems so far. Thank you. -- db

Re: arm: pmap uvm_fault findings

2016-07-27 Thread Mattieu Baptiste
> So, I found a suspicious place, added printfs, triggered the bug again > and voila, I think I got it. [...] > There are more places in that pmap where we explicitly check for zero > and not for being valid. Unfortunately this place was missed. > > Patrick > > diff --git

Re: arm: pmap uvm_fault findings

2016-07-27 Thread Artturi Alm
On Wed, Jul 27, 2016 at 08:06:57PM +0200, Patrick Wildt wrote: > On Tue, Jul 26, 2016 at 06:43:18PM +0200, Patrick Wildt wrote: > > Hi, > > > > I've been trying to debug a pmap issue on ARM. I have no solution, but > > I would like to share my findings so far. > > > > First of all, the

Re: arm: pmap uvm_fault findings

2016-07-27 Thread Mark Kettenis
> Date: Wed, 27 Jul 2016 20:06:57 +0200 > From: Patrick Wildt > > On Tue, Jul 26, 2016 at 06:43:18PM +0200, Patrick Wildt wrote: > > Hi, > > > > I've been trying to debug a pmap issue on ARM. I have no solution, but > > I would like to share my findings so far. > > > >

Re: arm: pmap uvm_fault findings

2016-07-27 Thread Patrick Wildt
On Tue, Jul 26, 2016 at 06:43:18PM +0200, Patrick Wildt wrote: > Hi, > > I've been trying to debug a pmap issue on ARM. I have no solution, but > I would like to share my findings so far. > > First of all, the panic/uvm_fault: > > > login: > uvm_fault(0xca06c858, 0, 1, 0) -> e > Fatal kernel