From: Hong Liu <hong.liu@intel.com>
Date: Mon, 19 May 2008 09:06:40 +0000 (+0800)
Subject: i915: check dummy page before freeing
X-Git-Tag: libdrm-2.4.3~16^2~181
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1cde3cc1ac467eb0527ed55127cf3bb983afde80;p=platform%2Fupstream%2Flibdrm.git

i915: check dummy page before freeing

The dummy read page will point to NULL if drm_bo_driver_init failed at
firstopen (modeset is not enabled), and will cause kernel oops at
subsequent drm_lastclose call, so be sure to check it.
---

diff --git a/linux-core/drm_bo.c b/linux-core/drm_bo.c
index 0470825..f2d3ceb 100644
--- a/linux-core/drm_bo.c
+++ b/linux-core/drm_bo.c
@@ -2361,10 +2361,12 @@ int drm_bo_driver_finish(struct drm_device *dev)
 	if (list_empty(&bm->unfenced))
 		DRM_DEBUG("Unfenced list was clean\n");
 
+	if (bm->dummy_read_page) {
 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,15))
-	ClearPageReserved(bm->dummy_read_page);
+		ClearPageReserved(bm->dummy_read_page);
 #endif
-	__free_page(bm->dummy_read_page);
+		__free_page(bm->dummy_read_page);
+	}
 
 out:
 	mutex_unlock(&dev->struct_mutex);