[PATCH 2/8] drm/panfrost: Fix a race in panfrost_ioctl_madvise()

[Daniel Vetter]

On Fri, Nov 29, 2019 at 02:40:34PM +0000, Steven Price wrote:
> On 29/11/2019 14:33, Boris Brezillon wrote:
> > On Fri, 29 Nov 2019 14:24:48 +0000
> > Steven Price <steven.price at arm.com> wrote:
> > 
> >> On 29/11/2019 13:59, Boris Brezillon wrote:
> >>> If 2 threads change the MADVISE property of the same BO in parallel we
> >>> might end up with an shmem->madv value that's inconsistent with the
> >>> presence of the BO in the shrinker list.  
> >>
> >> I'm a bit worried from the point of view of user space sanity that you
> >> observed this - but clearly the kernel should be robust!
> > 
> > It's not something I observed, just found the race by inspecting the
> > code, and I thought it was worth fixing it.
> 
> Good! ;) Your cover letter referring to a "debug session" made me think
> you'd actually hit all these.

Time for some igt to make sure this is actually correct?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch