[PATCH AUTOSEL 5.0 007/173] drm/msm: correct attempted NULL pointer dereference in debugfs

[Sasha Levin]

From: Brian Masney <masneyb at onstation.org>

[ Upstream commit 90f94660e53189755676543954101de78c26253b ]

msm_gem_describe() would attempt to dereference a NULL pointer via the
address space pointer when no IOMMU is present. Correct this by adding
the appropriate check.

Signed-off-by: Brian Masney <masneyb at onstation.org>
Fixes: 575f0485508b ("drm/msm: Clean up and enhance the output of the 'gem' debugfs node")
Signed-off-by: Sean Paul <seanpaul at chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190513234105.7531-2-masneyb@onstation.org
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/msm/msm_gem.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index c8886d3071fa3..bdf0089771bde 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -805,7 +805,8 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
 		seq_puts(m, "      vmas:");
 
 		list_for_each_entry(vma, &msm_obj->vmas, list)
-			seq_printf(m, " [%s: %08llx,%s,inuse=%d]", vma->aspace->name,
+			seq_printf(m, " [%s: %08llx,%s,inuse=%d]",
+				vma->aspace != NULL ? vma->aspace->name : NULL,
 				vma->iova, vma->mapped ? "mapped" : "unmapped",
 				vma->inuse);
 
-- 
2.20.1