Patch "drm: Release driver tracking before making the object available again" has been added to the 3.18-stable tree

gregkh
2017-08-27T12:33:17Z

This is a note to let you know that I've just added the patch titled

drm: Release driver tracking before making the object available again

to the 3.18-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
drm-release-driver-tracking-before-making-the-object-available-again.patch
and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.

>From fe4600a548f2763dec91b3b27a1245c370ceee2a Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Sat, 19 Aug 2017 13:05:58 +0100
Subject: drm: Release driver tracking before making the object available again
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From: Chris Wilson <chris@chris-wilson.co.uk>

commit fe4600a548f2763dec91b3b27a1245c370ceee2a upstream.

This is the same bug as we fixed in commit f6cd7daecff5 ("drm: Release
driver references to handle before making it available again"), but now
the exposure is via the PRIME lookup tables. If we remove the
object/handle from the PRIME lut, then a new request for the same
object/fd will generate a new handle, thus for a short window that
object is known to userspace by two different handles. Fix this by
releasing the driver tracking before PRIME.

Fixes: 0ff926c7d4f0 ("drm/prime: add exported buffers to current fprivs
imported buffer list (v2)")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Thierry Reding <treding@nvidia.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170819120558.6465-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/drm_gem.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -711,13 +711,13 @@ drm_gem_object_release_handle(int id, vo
struct drm_gem_object *obj = ptr;
struct drm_device *dev = obj->dev;

+ if (dev->driver->gem_close_object)
+ dev->driver->gem_close_object(obj, file_priv);
+
if (drm_core_check_feature(dev, DRIVER_PRIME))
drm_gem_remove_prime_handles(obj, file_priv);
drm_vma_node_revoke(&obj->vma_node, file_priv->filp);

- if (dev->driver->gem_close_object)
- dev->driver->gem_close_object(obj, file_priv);
-
drm_gem_object_handle_unreference_unlocked(obj);

return 0;

Patches currently in stable-queue which might be from chris@chris-wilson.co.uk are

queue-3.18/drm-release-driver-tracking-before-making-the-object-available-again.patch