drm/radeon: fix NULL pointer dereference in UMS mode

In UMS mode parser->rdev is NULL, so dereferencing
will cause an oops.

Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 396baba0141a..45151c49ce81 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -279,7 +279,7 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
                                   p->chunks[p->chunk_ib_idx].length_dw);
                         return -EINVAL;
                 }
-                if ((p->rdev->flags & RADEON_IS_AGP)) {
+                if (p->rdev && (p->rdev->flags & RADEON_IS_AGP)) {
                         p->chunks[p->chunk_ib_idx].kpage[0] = kmalloc(PAGE_SIZE, GFP_KERNEL);
                         p->chunks[p->chunk_ib_idx].kpage[1] = kmalloc(PAGE_SIZE, GFP_KERNEL);
                         if (p->chunks[p->chunk_ib_idx].kpage[0] == NULL ||
@@ -583,7 +583,8 @@ static int radeon_cs_update_pages(struct radeon_cs_parser *p, int pg_idx)
         struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
         int i;
         int size = PAGE_SIZE;
-        bool copy1 = (p->rdev->flags & RADEON_IS_AGP) ? false : true;
+        bool copy1 = (p->rdev && (p->rdev->flags & RADEON_IS_AGP)) ?
+                false : true;
 
         for (i = ibc->last_copied_page + 1; i < pg_idx; i++) {
                 if (DRM_COPY_FROM_USER(p->ib.ptr + (i * (PAGE_SIZE/4)),