[ 3.5.y.z extended stable ] Patch "drm/i915; Only increment the user-pin-count after" has been added to staging queue

[Herton Ronaldo Krzesinski]

This is a note to let you know that I have just added a patch titled

    drm/i915; Only increment the user-pin-count after

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Herton

------

>From 544f04c036aec7f900eed8644c3919ecd7c08462 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris at chris-wilson.co.uk>
Date: Wed, 2 Jan 2013 10:31:22 +0000
Subject: [PATCH] drm/i915; Only increment the user-pin-count after
 successfully pinning the bo

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 at chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
[ herton: adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski at 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