[PATCH 2/3] drm/vmwgfx: add local DRM_AUTH check for PRIME TO/FROM HANDLE

[Emil Velikov]

From: Emil Velikov <emil.velikov at collabora.com>

Realistically no drivers, but vmwgfx care about the DRM_AUTH flag here.

Follow-up work in this driver will properly isolate primary clients from
different master realms, thus we'll no longer need to parse _any_ ioctl
flags.

Until that work lands, add a local workaround.

Cc: VMware Graphics <linux-graphics-maintainer at vmware.com>
Cc: Thomas Hellstrom <thellstrom at vmware.com>
Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
---
I'd like to merge this through the drm-misc tree. Ack and rb are
appreciated.

Thanks
Emil
---
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 275d90fe2a25..32c18bb482a6 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1131,6 +1131,15 @@ static long vmw_generic_ioctl(struct file *filp, unsigned int cmd,
 	} else if (!drm_ioctl_flags(nr, &flags))
 		return -EINVAL;
 
+	/*
+	 * Little workaround until the vmwgfx patches providing isolation of
+	 * primary clients from different master realms lands.
+	 * With that work, we'll no longer need to parse _any_ ioctl flags.
+	 */
+	if (nr == 0x2d /* DRM_IOCTL_PRIME_HANDLE_TO_FD */ ||
+	    nr == 0x2e /* DRM_IOCTL_PRIME_FD_TO_HANDLE */)
+		flags != DRM_AUTH;
+
 	vmaster = vmw_master_check(dev, file_priv, flags);
 	if (IS_ERR(vmaster)) {
 		ret = PTR_ERR(vmaster);
-- 
2.21.0