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 mmp_path {
...
struct mmp_overlay overlays[0];
};
size = sizeof(struct mmp_path) + count * sizeof(struct mmp_overlay);
instance = kzalloc(size, GFP_KERNEL)
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, overlays, 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>
Link: https://patchwork.freedesktop.org/patch/msgid/20190807161312.GA26835@embeddedor
06b1f4b9f2