drm/gem: handlecount isn't really a kref so don't make it one.

There were lots of places being inconsistent since handle count
looked like a kref but it really wasn't.

Fix this my just making handle count an atomic on the object,
and have it increase the normal object kref.

Now i915/radeon/nouveau drivers can drop the normal reference on
userspace object creation, and have the handle hold it.

This patch fixes a memory leak or corruption on unload, because
the driver had no way of knowing if a handle had been actually
added for this object, and the fbcon object needed to know this
to clean itself up properly.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 4 insertions, 4 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_fbcon.c b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
index dbd30b2e43fd..d2047713dc59 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fbcon.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fbcon.c
@@ -352,6 +352,7 @@ nouveau_fbcon_destroy(struct drm_device *dev, struct nouveau_fbdev *nfbdev)
 
         if (nouveau_fb->nvbo) {
                 nouveau_bo_unmap(nouveau_fb->nvbo);
+                drm_gem_object_handle_unreference_unlocked(nouveau_fb->nvbo->gem);
                 drm_gem_object_unreference_unlocked(nouveau_fb->nvbo->gem);
                 nouveau_fb->nvbo = NULL;
         }
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index ead7b8fc53fc..19620a6709f5 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -167,11 +167,9 @@ nouveau_gem_ioctl_new(struct drm_device *dev, void *data,
                 goto out;
 
         ret = drm_gem_handle_create(file_priv, nvbo->gem, &req->info.handle);
+        /* drop reference from allocate - handle holds it now */
+        drm_gem_object_unreference_unlocked(nvbo->gem);
 out:
-        drm_gem_object_handle_unreference_unlocked(nvbo->gem);
-
-        if (ret)
-                drm_gem_object_unreference_unlocked(nvbo->gem);
         return ret;
 }
 
diff --git a/drivers/gpu/drm/nouveau/nouveau_notifier.c b/drivers/gpu/drm/nouveau/nouveau_notifier.c
index 3ec181ff50ce..3c9964a8fbad 100644
--- a/drivers/gpu/drm/nouveau/nouveau_notifier.c
+++ b/drivers/gpu/drm/nouveau/nouveau_notifier.c
@@ -79,6 +79,7 @@ nouveau_notifier_takedown_channel(struct nouveau_channel *chan)
         mutex_lock(&dev->struct_mutex);
         nouveau_bo_unpin(chan->notifier_bo);
         mutex_unlock(&dev->struct_mutex);
+        drm_gem_object_handle_unreference_unlocked(chan->notifier_bo->gem);
         drm_gem_object_unreference_unlocked(chan->notifier_bo->gem);
         drm_mm_takedown(&chan->notifier_heap);
 }