drm/i915: Warn before mmaping a purgeable buffer.

Only allow the user to mmap buffers that have not been marked as
purgeable.

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

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f4f714e39b7b..4755ba41bfef 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1431,6 +1431,14 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
 
         obj_priv = obj->driver_private;
 
+        if (obj_priv->madv != I915_MADV_WILLNEED) {
+                DRM_ERROR("Attempting to mmap a purgeable buffer\n");
+                drm_gem_object_unreference(obj);
+                mutex_unlock(&dev->struct_mutex);
+                return -EINVAL;
+        }
+
+
         if (!obj_priv->mmap_offset) {
                 ret = i915_gem_create_mmap_offset(obj);
                 if (ret) {