[PATCH v3 8/9] drm/rockchip: gem: Don't alloc/free gem buf when dev_private is invalid

Jeffy Chen
2017-04-05T08:31:48Z

After unbinding drm, the userspace may still has a chance to access
gem buf.

Add a sanity check for a NULL dev_private to prevent that from
happening.

Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
---

Changes in v3:
Address Daniel Vetter <daniel@ffwll.ch>'s comments.
Update commit message.

Changes in v2: None

drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index df9e570..205a3dc 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -184,6 +184,9 @@ static int rockchip_gem_alloc_buf(struct rockchip_gem_object *rk_obj,
struct drm_device *drm = obj->dev;
struct rockchip_drm_private *private = drm->dev_private;

+ if (!private)
+ return -ENODEV;
+
if (private->domain)
return rockchip_gem_alloc_iommu(rk_obj, alloc_kmap);
else
@@ -208,6 +211,11 @@ static void rockchip_gem_free_dma(struct rockchip_gem_object *rk_obj)

static void rockchip_gem_free_buf(struct rockchip_gem_object *rk_obj)
{
+ struct drm_device *drm = rk_obj->base.dev;
+
+ if (!drm->dev_private)
+ return;
+
if (rk_obj->pages)
rockchip_gem_free_iommu(rk_obj);
else
--
2.1.4