Messages in this thread | | | From | Kees Cook <> | Date | Thu, 23 Aug 2018 19:56:12 -0700 | Subject | Re: [PATCH] drm/sun4i: tcon-top: Use struct_size() in devm_kzalloc() |
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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 >
-- Kees Cook Pixel Security
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