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

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

[Chris Wilson]

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>
Cc: stable@vger.kernel.org
---
 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 3ab97c6..845cc04 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3557,14 +3557,15 @@ 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, false);
 		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
 	 */
-- 
1.7.10.4

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

[Daniel Vetter]

On Wed, Jan 02, 2013 at 10:31:22AM +0000, Chris Wilson wrote:
> 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>
> Cc: stable@vger.kernel.org

pin_vs_interrupt in i-g-t? In any case, applied to -fixes, thanks for the
patch.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch