[3.8.y.z extended stable] Patch "drm/ttm: Handle in-memory region copies" has been added to staging queue

[Kamal Mostafa]

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

    drm/ttm: Handle in-memory region copies

to the linux-3.8.y-queue branch of the 3.8.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-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.14.

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

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From f8f0599d88fb76646bdd8b735dc2574ad80c625d Mon Sep 17 00:00:00 2001
From: Jakob Bornecrantz <jakob at vmware.com>
Date: Wed, 30 Oct 2013 02:46:56 -0700
Subject: drm/ttm: Handle in-memory region copies
MIME-Version: 1.0
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commit 9a0599ddeae012a771bba5e23393fc52d8a59d89 upstream.

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

Signed-off-by: Jakob Bornecrantz <jakob at vmware.com>
Signed-off-by: Thomas Hellström <thellstrom at vmware.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 8be35c8..037f101 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -342,7 +342,9 @@ 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
--
1.8.3.2