[PATCH 20/74] drm/i915; Only increment the user-pin-count after successfully pinning the bo

[Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>]

3.5.7.4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris@chris-wilson.co.uk>

commit 93be8788e648817d62fda33e2998eb6ca6ebf3a3 upstream.

As along the error path we do not correct the user pin-count for the
failure, we may end up with userspace believing that it has a pinned
object at offset 0 (when interrupted by a signal for example).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[ herton: adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
---
 drivers/gpu/drm/i915/i915_gem.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 4dc8a9b..7605f40 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3125,14 +3125,15 @@ i915_gem_pin_ioctl(struct drm_device *dev, void *data,
 		goto out;
 	}
 
-	obj->user_pin_count++;
-	obj->pin_filp = file;
-	if (obj->user_pin_count == 1) {
+	if (obj->user_pin_count == 0) {
 		ret = i915_gem_object_pin(obj, args->alignment, true);
 		if (ret)
 			goto out;
 	}
 
+	obj->user_pin_count++;
+	obj->pin_filp = file;
+
 	/* XXX - flush the CPU caches for pinned objects
 	 * as the X server doesn't manage domains yet
 	 */
-- 
1.7.9.5