drm/msm/mdp5: check the return of kzalloc()

kzalloc() is a memory allocation function which can return NULL when
some internal memory errors happen. So it is better to check it to
prevent potential wrong memory access.

Besides, since mdp5_plane_reset() is void type, so we should better
set `plane-state` to NULL after releasing it.

Signed-off-by: Xiaoke Wang <xkernel.wang@foxmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/481055/
Link: https://lore.kernel.org/r/tencent_8E2A1C78140EE1784AB2FF4B2088CC0AB908@qq.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
index b176338..85ef10b 100644 (file)
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_plane.c
@@ -91,7 +91,10 @@ static void mdp5_plane_reset(struct drm_plane *plane)
                __drm_atomic_helper_plane_destroy_state(plane->state);
 
        kfree(to_mdp5_plane_state(plane->state));
+       plane->state = NULL;
        mdp5_state = kzalloc(sizeof(*mdp5_state), GFP_KERNEL);
+       if (!mdp5_state)
+               return;
 
        if (plane->type == DRM_PLANE_TYPE_PRIMARY)
                mdp5_state->base.zpos = STAGE_BASE;