| Message ID | 20180824010521.GA25451@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/sun4i: tcon-top: Use struct_size() in devm_kzalloc() | expand |
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 >
On Thu, Aug 23, 2018 at 07:56:12PM -0700, Kees Cook wrote: > 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> Applied, thanks! Maxime
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;
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> --- drivers/gpu/drm/sun4i/sun8i_tcon_top.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)