[Intel-gfx] [PATCH 9/9] 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 11c50e6..8d7e1dc 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3343,6 +3343,16 @@ 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