[PATCH 3.10 095/173] drm/ttm: Handle in-memory region copies

Greg Kroah-Hartman
2013-12-02T19:11:18Z

From: Jakob Bornecrantz <jakob@vmware.com>

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>

---
drivers/gpu/drm/ttm/ttm_bo_util.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- 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
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