On Thu, Aug 23, 2018 at 6:05 PM, Gustavo A. R. Silva gustavo@embeddedor.com wrote:

One of the more common cases of allocation size calculations is finding the size of a structure that has a zero-sized array at the end, along with memory for some number of elements for that array. For example:

struct foo { int stuff; void *entry[]; };

instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper:

instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com

Reviewed-by: Kees Cook keescook@chromium.org

-Kees

---

drivers/gpu/drm/sun4i/sun8i_tcon_top.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c index 55fe398..3040a79 100644 --- a/drivers/gpu/drm/sun4i/sun8i_tcon_top.c +++ b/drivers/gpu/drm/sun4i/sun8i_tcon_top.c @@ -129,8 +129,7 @@ static int sun8i_tcon_top_bind(struct device *dev, struct device *master, if (!tcon_top) return -ENOMEM;

•   clk_data = devm_kzalloc(dev, sizeof(*clk_data) +
  

•                           sizeof(*clk_data->hws) * CLK_NUM,
  

•   clk_data = devm_kzalloc(dev, struct_size(clk_data, hws, CLK_NUM),
                            GFP_KERNEL);
    if (!clk_data)
            return -ENOMEM;
  

-- 2.7.4