drm/i915: Mark the ggtt_view structs as packed (8d9046ad) · Commits · e / devices / android_kernel_fairphone_FP4

In the next few patches, we will depend upon there being no uninitialised bits inside the ggtt_view. To ensure this we add the __packed attribute and double check with a build bug that gcc hasn't expanded the struct to include some padding bytes. Signed-off-by:

Chris Wilson <chris@chris-wilson.co.uk> Reviewed-by:

Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170114002827.31315-2-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_gem_gtt.h

+12 −2

Original line number	Diff line number	Diff line
		@@ -156,12 +156,22 @@ struct intel_rotation_info {
		/* tiles */
		unsigned int width, height, stride, offset;
		} plane[2];
		};
		} __packed;

		static inline void assert_intel_rotation_info_is_packed(void)
		{
		BUILD_BUG_ON(sizeof(struct intel_rotation_info) != 8*sizeof(unsigned int));
		}

		struct intel_partial_info {
		u64 offset;
		unsigned int size;
		};
		} __packed;

		static inline void assert_intel_partial_info_is_packed(void)
		{
		BUILD_BUG_ON(sizeof(struct intel_partial_info) != sizeof(u64) + sizeof(unsigned int));
		}

		struct i915_ggtt_view {
		enum i915_ggtt_view_type type;