[PATCH -next] drm/i915: fix potential NULL pointer dereference in i915_gem_context_get_hang_stats()

[weiyj.lk at gmail.com (Wei Yongjun)]

From: Wei Yongjun <yongjun_wei at trendmicro.com.cn>

The dereference should be moved below the NULL test.

Signed-off-by: Wei Yongjun <yongjun_wei at trendmicro.com.cn>
---
 drivers/gpu/drm/i915/i915_gem_context.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index ff47145..f32107e 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -309,7 +309,7 @@ i915_gem_context_get_hang_stats(struct intel_ring_buffer *ring,
 				u32 id)
 {
 	struct drm_i915_private *dev_priv = ring->dev->dev_private;
-	struct drm_i915_file_private *file_priv = file->driver_priv;
+	struct drm_i915_file_private *file_priv;
 	struct i915_hw_context *to;
 
 	if (dev_priv->hw_contexts_disabled)
@@ -321,6 +321,7 @@ i915_gem_context_get_hang_stats(struct intel_ring_buffer *ring,
 	if (file == NULL)
 		return ERR_PTR(-EINVAL);
 
+	file_priv = file->driver_priv;
 	if (id == DEFAULT_CONTEXT_ID)
 		return &file_priv->hang_stats;