[Intel-gfx] [PATCH 11/11] drm/i915: check for multiple write domains in pin_and_relocate

[Daniel Vetter]

The assumption that an object has only ever one write domain is deeply
threaded into gem (it's even encoded the the singular of the variable
name). Don't let userspace screw us over.

Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/i915/i915_gem.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 7c4a7d9..515fe0e 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3363,6 +3363,16 @@ i915_gem_object_pin_and_relocate(struct drm_gem_object *obj,
 		}
 
 		/* Validate that the target is in a valid r/w GPU domain */
+		if (reloc->write_domain & (reloc->write_domain - 1)) {
+			DRM_ERROR("reloc with multiple write domains: "
+				  "obj %p target %d offset %d "
+				  "read %08x write %08x",
+				  obj, reloc->target_handle,
+				  (int) reloc->offset,
+				  reloc->read_domains,
+				  reloc->write_domain);
+			return -EINVAL;
+		}
 		if (reloc->write_domain & I915_GEM_DOMAIN_CPU ||
 		    reloc->read_domains & I915_GEM_DOMAIN_CPU) {
 			DRM_ERROR("reloc with read/write CPU domains: "
-- 
1.6.6.1