[Intel-gfx] [PATCH 1/3] RFC: drm: Restrict vblank ioctl to master

[Daniel Vetter]

Hi Rainer,

Awesome, thanks a lot for doing this! Any idea for when this will ship
in a release, and for how long your users are generally using older
releases? Just to have a rough indication for when we could attempt to
merge this patch here.

Cheers, Daniel

On Wed, Aug 8, 2018 at 5:35 PM, Rainer Hochecker <fernetmenta at kodi.tv> wrote:
> Finally we removed this code from Kodi.
>
> Regards,
> Rainer
>
> On Tue, Jun 14, 2016 at 11:02 AM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
>> Somehow this escaped us, this is a KMS ioctl which should only be used
>> by the master (which is the thing that's also in control of kms
>> resources). Everything else is bound to result in fail.
>>
>> Clients shouldn't have a trouble coping with this, since a pile of
>> drivers don't support vblank waits (or just randomly fall over when
>> using them). Note that the big motivation for abusing this like mad
>> seems to be that EGL doesn't have OML_sync, but somehow it didn't
>> cross anyone's mind that adding OML_sync to EGL would be useful. This
>> patch is meant to essentially start kicking that can from the back
>> end.
>>
>> Cc: fritsch at kodi.tv
>> Cc: fernetmenta at kodi.tv
>> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>> ---
>>  drivers/gpu/drm/drm_ioctl.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
>> index 0510675eec5d..6cc78d648393 100644
>> --- a/drivers/gpu/drm/drm_ioctl.c
>> +++ b/drivers/gpu/drm/drm_ioctl.c
>> @@ -529,9 +529,9 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
>>         DRM_IOCTL_DEF(DRM_IOCTL_SG_ALLOC, drm_legacy_sg_alloc, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
>>         DRM_IOCTL_DEF(DRM_IOCTL_SG_FREE, drm_legacy_sg_free, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
>>
>> -       DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_UNLOCKED),
>> +       DRM_IOCTL_DEF(DRM_IOCTL_WAIT_VBLANK, drm_wait_vblank, DRM_MASTER|DRM_UNLOCKED),
>>
>> -       DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, 0),
>> +       DRM_IOCTL_DEF(DRM_IOCTL_MODESET_CTL, drm_modeset_ctl, DRM_MASTER),
>>
>>         DRM_IOCTL_DEF(DRM_IOCTL_UPDATE_DRAW, drm_noop, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY),
>>
>> --
>> 2.8.1
>>



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch