Commit cd536db0 authored by Kees Cook's avatar Kees Cook
Browse files

dma-buf: Proactively round up to kmalloc bucket size 



Instead of discovering the kmalloc bucket size _after_ allocation, round
up proactively so the allocation is explicitly made for the full size,
allowing the compiler to correctly reason about the resulting size of
the buffer through the existing __alloc_size() hint.

Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221018090858.never.941-kees@kernel.org
parent e1789d7c

drivers/dma-buf/dma-resv.c

+7 −2
Original line number Diff line number Diff line
@@ -98,12 +98,17 @@ static void dma_resv_list_set(struct dma_resv_list *list, 
static struct dma_resv_list *dma_resv_list_alloc(unsigned int max_fences)

{

	struct dma_resv_list *list;

	size_t size;



	list = kmalloc(struct_size(list, table, max_fences), GFP_KERNEL);

	/* Round up to the next kmalloc bucket size. */

	size = kmalloc_size_roundup(struct_size(list, table, max_fences));



	list = kmalloc(size, GFP_KERNEL);

	if (!list)

		return NULL;



	list->max_fences = (ksize(list) - offsetof(typeof(*list), table)) /

	/* Given the resulting bucket size, recalculated max_fences. */

	list->max_fences = (size - offsetof(typeof(*list), table)) /

		sizeof(*list->table);



	return list;