From: Chris Wilson Date: Thu, 17 Nov 2016 15:58:46 +0000 (+0000) Subject: drm/i915: Add a few more sanity checks for stolen handling X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6288c79ea519f6ca3a54d87974b48ca6a8b986af;p=linux-beck.git drm/i915: Add a few more sanity checks for stolen handling We should never be called via obj->ops->release() on anything other than a fully formed stolen object, so raise that to an assert. In the process tidy up a comment and variable no longer used outside of a conditional BUG. Reported-by: kbuild test robot Signed-off-by: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/20161117155846.4631-1-chris@chris-wilson.co.uk Reviewed-by: Matthew Auld --- diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index 9b182ed93f3e..5bc9f699fdd2 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -513,11 +513,10 @@ i915_pages_create_for_stolen(struct drm_device *dev, u32 offset, u32 size) { struct drm_i915_private *dev_priv = to_i915(dev); - struct i915_ggtt *ggtt = &dev_priv->ggtt; struct sg_table *st; struct scatterlist *sg; - GEM_BUG_ON(offset > ggtt->stolen_size - size); + GEM_BUG_ON(offset > dev_priv->ggtt.stolen_size - size); /* We hide that we have no struct page backing our stolen object * by wrapping the contiguous physical allocation with a fake @@ -554,7 +553,7 @@ i915_gem_object_get_pages_stolen(struct drm_i915_gem_object *obj) static void i915_gem_object_put_pages_stolen(struct drm_i915_gem_object *obj, struct sg_table *pages) { - /* Should only be called during free */ + /* Should only be called from i915_gem_object_release_stolen() */ sg_free_table(pages); kfree(pages); } @@ -563,15 +562,16 @@ static void i915_gem_object_release_stolen(struct drm_i915_gem_object *obj) { struct drm_i915_private *dev_priv = to_i915(obj->base.dev); + struct drm_mm_node *stolen = fetch_and_zero(&obj->stolen); + + GEM_BUG_ON(!stolen); __i915_gem_object_unpin_pages(obj); - if (obj->stolen) { - i915_gem_stolen_remove_node(dev_priv, obj->stolen); - kfree(obj->stolen); - obj->stolen = NULL; - } + i915_gem_stolen_remove_node(dev_priv, stolen); + kfree(stolen); } + static const struct drm_i915_gem_object_ops i915_gem_object_stolen_ops = { .get_pages = i915_gem_object_get_pages_stolen, .put_pages = i915_gem_object_put_pages_stolen,