From: Chris Wilson Date: Wed, 3 Aug 2016 18:26:28 +0000 (+0100) Subject: drm: Declare that create drm_mm nodes with size 0 is illegal X-Git-Tag: v4.9-rc1~41^2~41^2~37 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=aafdcfd3f9aa3c9f77ae4e9385f21bf9ae120d3e;p=karo-tx-linux.git drm: Declare that create drm_mm nodes with size 0 is illegal At a higher level, all objects are created with definite size i.e. 0 is illegal. In forthcoming patches, this assumption is dependent upon in the drm_mm range manager, i.e. trying to create a drm_mm node with size 0 will have undefined behaviour. Add a couple of WARNs upon creating the drm_mm node to prevent later bugs. Signed-off-by: Chris Wilson Reviewed-by: David Herrmann Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1470248788-30873-1-git-send-email-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/drm_mm.c b/drivers/gpu/drm/drm_mm.c index 3f56d4b0cdae..11d44a1e0ab3 100644 --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -250,6 +250,9 @@ int drm_mm_reserve_node(struct drm_mm *mm, struct drm_mm_node *node) struct drm_mm_node *hole; u64 hole_start, hole_end; + if (WARN_ON(node->size == 0)) + return -EINVAL; + end = node->start + node->size; /* Find the relevant hole to add our node to */ @@ -317,6 +320,9 @@ int drm_mm_insert_node_generic(struct drm_mm *mm, struct drm_mm_node *node, { struct drm_mm_node *hole_node; + if (WARN_ON(size == 0)) + return -EINVAL; + hole_node = drm_mm_search_free_generic(mm, size, alignment, color, sflags); if (!hole_node) @@ -419,6 +425,9 @@ int drm_mm_insert_node_in_range_generic(struct drm_mm *mm, struct drm_mm_node *n { struct drm_mm_node *hole_node; + if (WARN_ON(size == 0)) + return -EINVAL; + hole_node = drm_mm_search_free_in_range_generic(mm, size, alignment, color, start, end, sflags);