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;
struct boo entry[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = devm_kzalloc(dev, size, 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);
Notice that, in this case, variable size is not necessary, hence it
is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
{
struct mmp_mach_plat_info *mi;
struct resource *res;
- int ret, i, size, irq;
+ int ret, i, irq;
struct mmphw_path_plat *path_plat;
struct mmphw_ctrl *ctrl = NULL;
}
/* allocate */
- size = sizeof(struct mmphw_ctrl) + sizeof(struct mmphw_path_plat) *
- mi->path_num;
- ctrl = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
+ ctrl = devm_kzalloc(&pdev->dev,
+ struct_size(ctrl, path_plats, mi->path_num),
+ GFP_KERNEL);
if (!ctrl) {
ret = -ENOMEM;
goto failed;