From: Jakob Bornecrantz <jakob@vmware.com>
Date: Wed, 30 Oct 2013 09:46:56 +0000 (-0700)
Subject: drm/ttm: Handle in-memory region copies
X-Git-Url: http://git.mmlx.us/?a=commitdiff_plain;h=f692d2d8bebddeb8c8faedfc41e4732f3dc23e5b;p=linux-edison.git

drm/ttm: Handle in-memory region copies

commit 9a0599ddeae012a771bba5e23393fc52d8a59d89 upstream.

Fix the case where the ttm pointer may be NULL causing
a NULL pointer dereference.

Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Thomas Hellström <thellstrom@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index af894584dd9..068341ad1f5 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -347,7 +347,9 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
 	if (old_iomap == NULL && ttm == NULL)
 		goto out2;
 
-	if (ttm->state == tt_unpopulated) {
+	/* TTM might be null for moves within the same region.
+	 */
+	if (ttm && ttm->state == tt_unpopulated) {
 		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
 		if (ret) {
 			/* if we fail here don't nuke the mm node