commit 11572a07f0aaf25357de5f8be27428bd33995c13
Author: Pierre Willenbrock <pierre@pirsoft.de>
Date:   Sat Oct 18 20:17:04 2008 +0200

    Add guard against highmem pages
    
    Signed-off-by: Pierre Willenbrock <pierre@pirsoft.de>

diff --git a/drivers/gpu/drm/drm_agpsupport.c b/drivers/gpu/drm/drm_agpsupport.c
index 3d33b82..7d40c81 100644
--- a/drivers/gpu/drm/drm_agpsupport.c
+++ b/drivers/gpu/drm/drm_agpsupport.c
@@ -480,8 +480,15 @@ drm_agp_bind_pages(struct drm_device *dev,
 		return NULL;
 	}
 
-	for (i = 0; i < num_pages; i++)
+	for (i = 0; i < num_pages; i++) {
 		mem->memory[i] = phys_to_gart(page_to_phys(pages[i]));
+		if (page_to_phys(pages[i]) >> 32) {
+			DRM_ERROR("Found physical page address outside "
+				  "of 32bit: %llx.\n", page_to_phys(pages[i]));
+			agp_free_memory(mem);
+			return NULL;
+		}
+	}
 	mem->page_count = num_pages;
 
 	mem->is_flushed = true;