On Fri, Aug 25, 2017 at 03:34:33PM +0200, Daniel Vetter wrote:
On Thu, Aug 24, 2017 at 11:04:01AM +0100, Brian Starkey wrote:
Hi,
Thanks for the CC.
On Fri, Aug 18, 2017 at 06:13:14PM +0200, Noralf Tr??nnes wrote:
> (cc affected parties)
>
>
> Den 18.08.2017 09.46, skrev Daniel Vetter:
> > On Thu, Aug 17, 2017 at 06:21:30PM +0200, Noralf Tr??nnes wrote:
> > > Reject mapping an imported dma-buf since is's an invalid use-case.
> > >
> > > Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> > > Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > > Cc: Sean Paul <seanpaul@xxxxxxxxxxxx>
> > > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> > > Signed-off-by: Noralf Tr??nnes <noralf@xxxxxxxxxxx>
> > I think acks from someone using mali would be good too. amdgpu already has
> > such checks, so I think on the desktop side we're ok.
> >
This looks like it would break anyone running the Mali-4xx series GPUs
with the Arm graphics stack (e.g. Hikey board).
I don't know where that sits in terms of policy.
Why would this break this use-case? Is the mali blob somehow using dumb
mmap for it's own buffers it shares with display? That would be rather
backwards ...
If it's running with a DRM display driver (which may or may not be
Mali-DP, they are separate IPs), then its window system code always
uses dumb mmap if it needs a pointer. That might be a native DRM
buffer that the display driver allocated, or a dma-buf which it PRIME
imported (which would now fail).
-Brian
Either way, blob -> meh, not a concern really.
-Daniel
Cheers,
-Brian
> > Acked-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> >
> > But I think this one here definitely needs a few more acks. I could break
> > uabi if we're unlucky, so let's not rush it.
>
> Ok, I've CC'ed the affected parties to increase the odds that they look
> at this. These are the drivers using drm_gem_dumb_map_offset()
> (hopefully I got the list right):
>
> arc
> atmel-hlcdc
> cirrus
> exynos
> fsl-dcu
> gma500
> hdlcd
> imx
> kirin
> mali-dp
> mediatek
> meson
> mxsfb
> pl111
> rcar-du
> rockchip
> shmobile
> sti
> stm
> sun4i
> tegra
> tilcd
> vc4
> zte
>
>
> Noralf.
>
> > -Daniel
> >
> > > ---
> > > drivers/gpu/drm/drm_gem.c | 6 ++++++
> > > 1 file changed, 6 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> > > index ad4e9cf..8da5801 100644
> > > --- a/drivers/gpu/drm/drm_gem.c
> > > +++ b/drivers/gpu/drm/drm_gem.c
> > > @@ -333,6 +333,12 @@ int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
> > > if (!obj)
> > > return -ENOENT;
> > > + /* Don't allow imported objects to be mapped */
> > > + if (obj->import_attach) {
> > > + ret = -EINVAL;
> > > + goto out;
> > > + }
> > > +
> > > ret = drm_gem_create_mmap_offset(obj);
> > > if (ret)
> > > goto out;
> > > --
> > > 2.7.4
> > >
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
